O b s e r vingS a r t h t e m E THE EARTH OBSERVER · 2017-01-26 · off the coast of Japan (Hekurajima and Aogashima), • AMR flights in May-July 2000 over Nagaoka, • one ground-based

In this issue

Ear

thObserving System

THE EARTH OBSERVER

A Bimonthly EOS Publication May/June 1999 Vol. 11 No. 3

EDITOR’S CORNER CORNERMichael KingEOS Senior Project Scientist

SCIENCE TEAM MEETINGS

Joint Advanced Microwave Scanning Radiometer(AMSR) Science Team Meeting ........................ 3

Report on the EOS CHEM Science TeamMeeting ............................................................. 4

CERES Science Team Meeting ........................ 5

Moderate Resolution Imaging Spectro-radiometer(MODIS) Science Team Meeting Summary .... 10

The First PICASSO-CENA Science TeamMeeting Minutes .............................................. 20

Summary of the Mini-SWAMP Meeting ........... 26

Summary of NASA EOS SAFARI 2000Workshop ........................................................ 32

SCIENCE ARTICLES

A Portable Integrating Sphere Source forRadiometric Calibrations from the Visible tothe Short-Wave Infrared .................................. 14

Global Observations of Aerosols and Cloudsfrom Combined Lidar and Passive Instrumentsto Improve Radiation Budget and ClimateStudies ............................................................ 22

An Associate of Arts in Community Collegesfor Training in Earth Science Project ............... 27

MODIS Land Surface Temperature Validation . 29

Report of EOS Volcanology IDS TeamMeeting ........................................................... 36

NASA’s Earth Science Enterprise Participatesin the Odyssey of the Mind World Finals ......... 38

ANNOUNCEMENTS

Major Accomplishment ...................................... 4

EOS Scientists in the News ............................ 40

Earth Science Education Program Update ..... 42

Information/Inquiries ......................... Back cover

I’m happy to report that onJune 19, NASA’s QuickScatterometer (QuikSCAT)satellite was launched aboardan Air Force Titan II launchvehicle from Vandenberg AirForce Base. QuikSCAT’sSeaWinds microwavescatterometer will provide newnear-surface wind speed anddirection measurements under all weather and cloud conditions overthe Earth’s oceans. The satellite achieved its initial elliptical orbit witha maximum altitude of about 800 km above the Earth’s surface aboutan hour after launch.

During the first two weeks after launch, QuikSCAT fired its thrustersas many as 25 times to circularize and gradually fine-tune its polarorbit. Eighteen days after launch, the SeaWinds instrument wasturned on for the first time. Members of the project engineering andscience teams spent the next 12 days performing detailed checks ofthe instrument and initially calibrating its radar backscatter and oceanwind measurements. Although calibration and validation of themeasurements will continue for several months, QuickSCAT formallybegan its primary mission of mapping ocean wind speed anddirection, starting about 30 days after launch. The primary mission isscheduled to continue for two years.

QuikSCAT is managed for NASA’s Office of Earth Science by the JetPropulsion Laboratory, which also built the SeaWinds scatterometerinstrument and will provide ground science processing systems.NASA’s Goddard Space Flight Center managed development of thesatellite, designed and built by Ball Aerospace & Technologies Corp.,

THE EARTH OBSERVER • May/June, 1999 Vol. 11 No. 3

2

Boulder, CO. Additional information onQuikSCAT can be found on the QuikSCATweb site at http://winds.jpl.nasa.gov/missions/quikscat/quikindex.html.

Launch of the EOS flagship satellite Terra(formerly known as AM-1) has beendelayed until no earlier than September13, 1999. A rash of Pratt & Whitney RL-10engine failures on Delta launch vehicles(similar to the Atlas IIAS vehicle slated tolaunch Terra) prompted the decision topostpone the launch. Consequently, aflight constraint on the RL-10 engine hasbeen issued by Pratt & Whitney. With theuncertainty of the resolution of the flightconstraint, NASA has decided not toproceed with preparations for fueling theTerra spacecraft (the next major step in thelaunch flow). Terra will not be launcheduntil there is the highest confidence thatall aspects of the launch will meet withsuccess.

The EOS Project Science Office and theGoddard Public Affairs Office organized aScience Writers Workshop at the AmericanGeophysical Union headquarters inWashington, DC on June 24. The goal ofthe meeting was to educate sciencejournalists from Nature, Scientific American,Discovery On-Line, Physics Today, and otherpublications on the EOS programs, global-change science objectives, and informationresources. Several prominent scientistsand NASA officials spoke on EOS mis-sions, science, and media resources. OnJune 25, workshop participants attended aseries of lectures and demonstrations byEOS project and data managers atGoddard Space Flight Center. An EOSGlobal Change Media Directory was alsodistributed at the workshop. The MediaDirectory provides journalists with aready source of international expertise onglobal climate change and policy. The 237scientists listed in the directory represent

more than 30 scientific disciplines empha-sized by the EOS program. The workshopand Media Directory together represent aninvaluable resource for accurate andtimely dissemination of EOS mission andscience information to major mediaoutlets.

Landsat 7 continues to perform very wellthree months after its successful launchfrom Vandenberg Air Force Base on April15. Since then, in addition to the normalpost-launch checkout activity, a great dealof effort has been devoted to extractingand publicizing a few scenes for mediaand public relations purposes. TheLandsat 7 Team is now returning to thecritical task of completing the on-orbitindependent verification plan required toacclimate the instrument to its spaceenvironment. Landsat 7 imagery has nowbeen geo-referenced to the WorldwideReference System (WRS) Path-Rowcoordinate system. This milestoneachievement allows consistent correlationwith other Landsat imagery, and opens thedoor for operational data acquisition andordering. Landsat 7’s orbit is now 8 daysout of phase with Landsat 5, providingmaximum Earth coverage for monitoringacute geophysical phenomena like floods,forest fires, and other natural disasters.The first Landsat 7 imagery was madeavailable to the public in late July. Fullscenes that have been corrected for sensoreffects and spacecraft geometry (LevelOne processing) will become availablefrom the EROS Data Center in Sioux Falls,South Dakota at a price of $600 each. Moreinformation on Landsat 7 and the Landsatprogram can be found on the Landsatprogram web site at: http://geo.arc.nasa.gov/sge/landsat/landsat.html.

The EOS Data and Information System(EOSDIS) recently conducted data flow

and ingest/archive/distribution readinesstests, complemented by Terra End-to-endScience System (TESS) tests. A MissionOperations and Science System (MOSS)also took place in late July. These testshave revealed satisfactory networkperformance for the current requirements,but the network may not be able tosupport system distribution throughputfor significant requirement increases.Much of the processing for EOS data willbe done via Science Investigator-ledProcessing Systems (SIPS), and willcontain high-speed ingest capabilities fordata products in the next major release ofEOSDIS software, which will be installedat the DAACs beginning in late July, andextending through November. Allprocessing, ingest, and distributionsoftware is expected to be in place in timefor operational data flow from Terra.


3

A Joint AMSR Science Team meeting washeld in Firenze, Italy, 19 March 1999,immediately following the Microrad ’99Specialists meeting. Most of the discussionrevolved around validation of the AMSRproducts. A summary of the JapaneseValidation plan was presented.

Dr. A. Shibata (ADEOS-II AMSR LeadScientist) presented a summary of theJapanese Validation plan, including thestatus of the AMR aircraft-radiometerrefurbishment. The pre-launch activities(1999-2000) rely mostly on generating‘match-up’ data sets with SSM/I and TMI.The data used to generate these data setswould be from radiosondes, buoys,radars, and GTS-provided snow-depthmeasurements. Soil-moisture data willcome from GAME IOP in Tibet andThailand and SGP’99. The field experi-ments and campaigns considered are:

• continuous monitoring of twoground-based radiometers on islandsoff the coast of Japan (Hekurajimaand Aogashima),

• AMR flights in May-July 2000 overNagaoka,

• one ground-based radar in the Bay ofWakasa, and possibly one in Siberia,

• an automatic snow-station networkin Siberia.

The post-launch validation would consistof a continuation of the pre-launchactivities. These activities will be aug-mented by:

• AMR flights in May-July 2001 inTibet, for precipitation validation

• AMR, AMSS, PSR, AVIRIS, air-bornelaser altimeter, and SAR flights in theOkhotsk Sea, Arctic and AntarcticOceans, and Alaska, for sea-icevalidation,

• campaigns in Tibet and Siberia tomeasure snow depth, density, andgrain size in Jan-Feb 2001 and 2002,for snow validation,

• AMR flights in Tibet, May-July 2001,Thailand, April-June 2002, andMongolia, Aug-Oct 2002, for soil-moisture validation.

The AMR is undergoing a major refurbish-ment. The main change is an improved in-flight calibration scheme. There will be 3test flights to validate the correct perfor-mance of the AMR. E. Sakai (NASDA/EOSD) presented to the Joint Science teamthe results from the February data formatmeeting; both instruments will have thesame data format, and this format will bethe same as the EOSDIS-recommendeddata format.

C. Kummerow (AMSR-E Precipitationgroup lead) presented a detailed summaryof the updated AMSR-E PrecipitationValidation Plan. The main components ofthis plan are: 1) Extending the TRMMground-radar network to higher latitudes,2) operating the mobile (10 cm) radar (toobtain beam-filling statistics, 3) freezing-level retrieval, vertical-profile statistics,cumulus/stratus confirmation), and 4) anintensive field campaign (using the ER 2and a microphysics aircraft), in 2002 inAlaska/Seattle. A similar mission isplanned for 2004 in Punta Arenas, Chile.

F. Wentz (AMSR-E Ocean suite lead)showed some results from his TMI work,where he found wind-speed (roughness)anomalies upwind of Hawaii and off thesouthern tip of Africa. He discussed apossible validation plan for the wind andSST retrievals in these areas.

P. Gudmansen (Professor emeritus,Technical University of Denmark)presented his proposal for GRASP, avalidation campaign for sea ice in theArctic Ocean, near the north coast of

Joint Advanced Microwave ScanningRadiometer (AMSR) Science TeamMeeting— E. Lobl ([email protected]), AMSR-E Science Team Coordinator, Earth

System Science Laboratory, University of Alabama in Huntsville

(Continued on page 19)

ADEOS-II AMSR homepage:se.eorc.nasda.go.jp/eorc/AMSR/amsr EOS

PM-1 AMSR-E homepage:wwwghcc.msfc.nasa.gov/AMSR


4

MajorAccomplishment:

The PICASSO-CENA proposal (Dr.David Winker, principal investigator)was selected for development underthe NASA Office of Earth Science’sEarth System Science Pathfinder(ESSP) program. PICASSO-CENA isthe next phase in NASA’s strategy tounderstand the impact of aerosolsand clouds on the Earth’s climatesystem. The primary goal of themission is to provide global, high-spatial-resolution measurements ofthe vertical distribution and opticalproperties of tropospheric aerosolsand clouds that will significantlyimprove our understanding of theeffects of aerosols and clouds on theEarth’s radiation budget. It combinesa 3-channel lidar with innovativepassive sensors to obtain this uniquedata set. A key aspect of PICASSO-CENA is flying in formation withNASA’s EOS-PM and CloudSatsatellites to produce a coincidentglobal data set that is essential foraccurate quantification of aerosol andcloud radiative effects. PICASSO-CENA is a joint enterprise betweenthe NASA Langley Research Center(LaRC), the French Centre Nationald’Etudes Spatiales (CNES) andInstitut Pierre Simon Laplace (IPSL),Ball Aerospace and TechnologiesCorporation (BATC), HamptonUniversity (HU), and other universitypartners. The PICASSO-CENAspacecraft will be launched in 2003and will operate for 3 years.

An EOS CHEM science team meeting washeld April 12-14, 1999 (Monday – Wednes-day) at the Convention Center in Pasa-dena CA. The CHEM Project now has twomeetings annually. The spring meeting isoriented towards data products andscience issues which are anticipated to beaddressed using CHEM data, while thefall meeting [the Chemistry Annual ProjectSteering Meeting (CHAPS)] is orientedtowards project issues. The April 1999meeting had two purposes. The first wasto enhance the CHEM science team bydeveloping interactions between the dataproviders (instrument teams and their PIs)and data users (IDS investigators, mem-bers of the instrument science teams notdirectly involved in data production, andthe outside science community). Thesecond was to discuss validation needs forCHEM. The agenda included presenta-tions on the four CHEM instruments: theMicrowave Limb Sounder (MLS), HighResolution Dynamics Limb Sounder(HIRDLS), Tropospheric EmissionSpectrometer (TES), and Ozone Monitor-ing Instrument (OMI), and presentationson sources of data in the CHEM timeframesuch as the Solar Stellar IrradianceComparison Experiment (SOLSTICE), andthe ENVISAT mission, which ESA willlaunch in 2000. There was also a presenta-tion on the planned standard dataassimilation products expected in supportof the mission. In addition, there weremore than 30 contributed science talks andposters.

The CHEMProject hasdeveloped WorkingGroups to address variousproject needs. The currentgroups are: Data Systems, MissionOperations, Education/Outreach,Algorithm, and Validation. The WorkingGroups met at various times during thefirst two days of the meeting, and reportedto the full group on Wednesday. WorkingGroup reports from this meeting andgeneral information about these sub-groups can be found on the CHEM website (http://eos-chem.gsfc.nasa.gov). Partof the final morning was spent discussingvalidation needs for EOS CHEM, and thegoal of planning validation campaignsthat will meet the dual goals of satisfyingCHEM needs while addressing focussedscience questions. A presentation on theSAGE III Ozone Loss and ValidationExperiment (SOLVE) provided a concreteexample of this strategy. Discussion at thismeeting was focussed on the validationneeds of the CHEM platform, emphasiz-ing that several constituents are measuredby more than one instrument. Sciencequestions to be addressed in the mannerof SOLVE, while fulfilling these validationneeds, will be the subject of the Workshopfor Integration of Satellite Calibration/Validation and Research-Oriented FieldMissions in the Next Decade to be held inAugust 1999 in Snowmass, CO.

Report on the EOS CHEM ScienceTeam Meeting— Anne Douglass ([email protected]), NASA Goddard Space Flight

Center, Greenbelt, MD


5

The 19th Clouds and the Earth’s RadiantEnergy System (CERES) Science Teammeeting was held in Williamsburg, VA onApril 27-29, 1999. The major items ofbusiness for this meeting were: (1)identifying current problems in cloudvalidation and expected ways of reducingthose to a level acceptable for validationand archiving; (2) identifying currentproblems in CERES Surface and Atmo-spheric Radiation Budget (SARB) valida-tion and expected ways of reducing thoseproblems to a level acceptable for valida-tion and archiving; (3) clarifying theapproaches to improving angular distribu-tion models (ADMs) and identifying whenwe begin producing the second edition ofthe CERES-Tropical Rainfall MeasuringMission (TRMM) products; and (4)ensuring that the instrument calibration isstable, that we optimize the time of datacollection for CERES-TRMM, are fullyprepared to rapidly validate the AM(Terra) data, and that we have a firm andrigorous basis for stating the uncertaintiesin the CERES measurements

Bruce Wielicki (NASA Langley ResearchCenter, LaRC), CERES Co-PrincipalInvestigator, opened the meeting with anEOS program status report. The EarthObserving System morning satellite(Terra) is now scheduled to be launchedno sooner than September 13, 1999. EOS-PM is still on schedule for a December2000 launch.

Instrument Status: TRMM, Terra,and EOS-PM

Leonard Kopia (LaRC) presented details ofthe investigation into the voltage con-verter anomaly on the CERES instrumentflying on the TRMM spacecraft. The teamrecommended replacement of all low-voltage converters in the five CERES flightmodels. Kopia also reported that allinstrument build and test activities are onschedule. Kory Priestley (LaRC) showedthat calibration goals continue to be metand exceeded. Ground-to-orbit calibra-tions are consistent to within 0.12, 0.08,and 0.29% for the total, window, andshortwave (SW) channels, respectively.On-orbit results show no significant gainchange in any channel. Bruce Wielickireviewed the CERES/TRMM operationsstrategy for supporting field experiments.The first priority is to conserve theinstrument until the Terra launch toconduct intercalibrations between the twoCERES instruments. Robert B. Lee III(LaRC) discussed Terra launch readinessand on-orbit operations for calibrationsand consistency checks.

ERBE-like Data and Validation

Dave Young and Richard Green (both ofLaRC) gave an update on ERBE-likevalidation. A comparison of tropicalmeans from CERES during 1998 and EarthRadiation Budget Satellite (ERBS) scanner

5-year averages from 1985-89 showedsignificant differences. The agreement inclear-sky values and the disagreement inall-sky values indicates that changes incloud properties between the EarthRadiation Budget Experiment (ERBE) andCERES time periods are responsible forthe differences.

Yong Hu (Hampton University, HU)examined the discrepancy betweentheoretical and observed cloud absorption.Using the Precipitation Radar on TRMMto identify deep convective clouds, hedetermined from the correspondingCERES measurements that the meanalbedo of such clouds is about 0.70 forprecipitating deep convection and 0.74 fornon-precipitating deep convection. Allclouds gave 11-µm brightness tempera-tures <205 K. Theoretical albedos rangedfrom 0.74 to 0.79.

Patrick Minnis (LaRC) gave an overviewof the CERES cloud optical propertyretrieval subsystem and showed goodinitial results for cloud physical andmicrophysical property retrievals. TheVisible-Infrared Scanner (VIRS) calibrationappears to be stable. Surface-basedretrievals of cloud properties at theAtmospheric Radiation Measurement(ARM) Southern Great Plains (SGP) andthe Tropical Western Pacific (TWP) sitescompared well with CERES-derived cloudproperties.

Norman Loeb (HU) summarized recentfindings of the ADM team. Albedoestimates based on ADMs using fixedoptical-depth classes show a largedependence on viewing geometry.Albedos based on ADMs which usepercentiles of cloud optical depth showsubstantially less dependence on viewinggeometry and agree with direct integra-tion albedos. Results from the Polarizationand Directionality of the Earth’s

CERES Science Team Meeting— Gary G. Gibson ([email protected]),

NASA Langley Research Center— Shashi K. Gupta ([email protected]),

NASA Langley Research Center


6

Reflectances (POLDER) experimentdemonstrated the importance of definingADMs by cloud fraction, cloud opticaldepth, and cloud phase.

Tom Charlock (LaRC) presented a statusreport on the validation of SARB dataproducts. He noted several improvementsto the radiative transfer code, and re-viewed several ongoing validationexperiments.

Education and Outreach

Lin Chambers (LaRC) gave a brief updateon recent activities of the Students’ CloudObservations On-Line (S’COOL) project,which is a part of the Outreach andEducation programs at NASA/LaRC.Under this project, students in secondaryschools around the world make observa-tions of the atmosphere and submit themto the S’COOL database. These observa-tions are then used for validation ofcoincident satellite data. At present, over250 schools from the U.S. and 20 othercountries on all continents are participat-ing in the S’COOL project.

Invited Presentations

Two EOS Earth Science System Pathfinder(ESSP) missions have been selected to flyin formation with EOS-PM to providecloud profiling data. The PathfinderInstruments for Cloud and AerosolSpaceborne Observations - ClimatologieEtendue des Nuages et des Aerosols(PICASSO-CENA) includes a lidarinstrument, and the CloudSat mission willfly a cloud radar. Dave Winker (LaRC)gave an overview of the PICASSO-CENAmission. The payload consists of a lidar, anoxygen A-band spectrometer, an imaginginfrared radiometer, and a wide-field-of -view camera. Data from these instrumentswill be used to measure the verticaldistributions of aerosols and clouds in the

atmosphere, as well as optical andphysical properties of aerosols and cloudswhich influence the Earth’s radiationbudget. Taneil Uttal (NOAA) gave a briefsummary of CloudSat capabilities forobtaining vertical profiles of clouds. Shethen described the SHEBA (Surface HeatBudget of the Arctic) experiment andshowed some results on observations ofArctic clouds using lidar and radarinstruments.

Working Group Reports

Instrument Working Group: Robert B. LeeIII led the Instrument Working Group(WG) meeting in discussions of theaccuracy of the CERES instrument onTRMM. Measurement accuracy andprecision goals have been satisfied. Thegroup is examining the instrument groundcalibration data in an attempt to under-stand the 1% inconsistency in the ERBE-like 3-channel checks performed by KoryPriestley for deep convective clouds(0.8%), and Richard Green on the TropicalMean day/night check (1.2%). Thisinconsistency is within the CERES goal of1% SW absolute calibration accuracy;calibration changes are not currentlyplanned.

Cloud Working Group: Patrick Minnis led adiscussion of cloud retrieval, archival,data dissemination, and validation issues.

Q. Han (U. Alabama-Huntsville) dis-cussed the uncertainties in cloud retrievalsinduced by the variation of ice crystalshapes in clouds. He quantified largeuncertainties caused by inaccurate icecrystal shapes, which are reflected in largeerrors in bidirectional reflectance func-tions and optical depth.

Ron Welch (U. Alabama-Huntsville) gaveexamples of a new cloud classifier thatutilizes VIRS data. He also presented

results for a 3-D cloud study in which hesimulated radiance patterns in order tostudy the errors inherent in using plane-parallel radiative-transfer theory insatellite retrievals.

Qing Trepte (SAIC) presented improve-ments to the CERES cloud-maskingtechniques for both day and night time.Pat Heck, Analytical Services and Materi-als, Inc. (AS&M), discussed improvedtechniques implemented in the cloudoptical property retrieval algorithm fordetermining cloud phase using 1.6-µmdata. Sunny Sun-Mack (SAIC) presentednew databases of 1.6-µm clear-skyproducts, including maps of 1.6-to-0.63-µm reflectance ratios that are used in thecloud mask. Michael King (GSFC)commented that he could provide newdirectional and bidirectional models forsnow and ice that would assist with cloudmasking.

Jay Mace (U. Utah) summarized cloudproperty retrievals from the ARM pro-gram. The availability of data from theSGP, TWP, and North Slope of Alaska siteswas included in discussion of CERESvalidation. Michael King suggested thathe reduce the data volume for the CERESteam by matching the surface-basedretrievals with TRMM and Terra over-passes.

Chuck Long (Penn State) presented asummary of his cloud-cover retrievalsfrom a NOAA hemispheric sky imager,including a comparison of these retrievalswith cloud amounts derived from satellitedata using the Layered Bispectral Thresh-old Method of Minnis.

Surface and Atmospheric Radiation Budget

(SARB) Working Group: The SARB andSurface-only Working Groups met jointly.The meeting was co-chaired by ThomasCharlock and David Kratz (both fromLaRC).


7

Bill Collins (NCAR) gave an invitedpresentation on the results from anexperiment in which aerosol radiativeproperties were forecast over areas of theIndian Ocean. In the first part of thisexperiment, a chemical transport model(CTM) was used with aerosol sources andmeteorological data to produce theforecast. In the second part, satellite datawere assimilated with the CTM. Compari-sons of the forecasts with and withoutsatellite data assimilation showed signifi-cant differences.

Fred Rose (AS&M) gave a report on awide range of SARB activities. Roseshowed comparisons of several SW andlongwave (LW) parameters derived in theSARB subsystem with correspondingsingle-satellite-footprint (SSF) parametersfrom satellite retrievals. Comparison ofcalculated and observed top-of-atmosphere(TOA) albedos over cloudy scenes showedsignificant differences as a function ofcloud optical depth and phase. These wereattributed to the lack of sensitivity tocloud optical depth and phase in theADMs used in CERES processing. Rosealso showed that the inclusion of theCERES window channel in the constrain-ment algorithm helped to better constrainthe lower tropospheric humidity (LTH)and the surface skin temperature. Severalimprovements were implemented in theFu-Liou model and SARB processing as aresult of these studies.

John Augustine (NOAA) and Chuck Longapprised the WG of surface-measureddata available from six locations of theNOAA SURFRAD network for validationof CERES/SARB products. Augustinedescribed the instrumentation and theradiation and ancillary measurementsmade at these facilities. Long described aninnovative method for estimating effectivecloud amounts at a site directly from thesolar radiation measurements.

Tim Alberta (AS&M) presented results ofan analysis of surface-measured fluxesfrom the CERES/ARM/GEWEX Experi-ment 2 (CAGEX2) and the CERES ARMValidation Experiment (CAVE). In many ofthese measurements, the diffuse radiationwas substantially less than that computedwith the Fu-Liou code even withoutaerosols. Many of the pyranometersregistered negative values for diffuseradiation during the night. The magnitudeof these negative values was found to berelated to the net LW flux at the instru-ment. A correction algorithm for diffuseradiation was developed based on thisrelationship, and daytime diffuse-radiation measurements were correctedusing this algorithm.

Martial Haefflin (Virginia PolytechnicInstitute & State University, VPI&SU)presented results of a simulation ofphysical processes inside a pyranometer,which can be used to quantify uncertain-ties in SW radiation measurements.Haefflin showed that monitoring thetemperature of the inner dome is impor-tant for modeling the energy exchangesbetween the detector and the surround-ings.

Seiji Kato (HU) compared CERES re-trieved and modeled TOA irradiances forscenes containing warm stratus clouds.Cloud parameters used in the modelcomputations were based on measure-ments made at the ARM SGP site inJanuary 1998. He concluded that CERESretrievals overestimated TOA albedo overthick clouds, and underestimated it overthin clouds, and he stressed the need forstratifying ADMs by cloud optical depth.

John Augustine apprised the group of theGlobal Air-ocean IN-situ System (GAINS),a NOAA program from which valuabledata can be obtained for validation ofCERES retrievals. The GAINS program

launches 60-ft-diameter balloons, whichcarry a 200-lb payload and stay at 60-70-thousand feet for extended periods oftime. These balloons will make radiomet-ric measurements and launch dropsondes.

Thomas Charlock (LaRC) apprised thegroup of the Ultra Long Duration Balloon(ULDB) program being planned byNASA/GSFC and the Wallops Islandfacility. These balloons will stay at about35 km for extended periods of time, andwill carry Eppley pyranometers and otherscientific payloads. The first balloon willbe launched in the Southern Hemispherein December 2000, and will stay up forabout 30 days. Subsequent balloons willstay up for up to 100 days.

Shashi Gupta (AS&M) discussed theproblem faced by the Meteorology, Ozone,and Aerosol (MOA) subsystem duringMay-June 1998 because of the interruptionof the ozone data stream from the Strato-spheric Monitoring-group Ozone BlendedAnalysis (SMOBA/NCEP) which is theprimary source of ozone for MOA. Hepresented a plan to deal with suchinterruptions in the future.

CERES ADM Working Group: NormanLoeb led the ADM WG meeting with ageneral overview of critical ADM/inversion research issues.

Yong Hu showed some early comparisonsbetween clear-sky SW BidirectionalReflectance Distribution Functions(BRDFs) from CERES Rotating AzimuthPlane Scanner (RAPS) data with thosefrom theory. Overall, the CERES BRDFstend to show more limb brighteningrelative to theory. One possible cause forthis may be cloud contamination ofoblique CERES-RAPS views not observedby the VIRS on TRMM, which observesthe scenes only at near-nadir viewingzenith angles. Hu’s results emphasize the


8

need for a means of improving cloudscreening for shallow CERES viewingzenith angles.

Lin Chambers (LaRC) presented results ofa theoretical examination of NormanLoeb’s “percentile-approach” for con-structing ADMs. She found that retrievedfluxes show smaller angular bias and rmserrors using the percentile-approach thanthe “fixed-tau” approach (which ignoresretrieval errors in determining ADM scenetypes). She points out, however, that eventhe percentile approach does not entirelycorrect for the influence of 3D cloudeffects (e.g., shadowing in the forwardscattering direction).

Shalini Mayor (AS&M) presented spectralclear-sky BRDFs over the ARM SGP siteinferred from the Unmanned AerospaceVehicle (UAV) Multispectral PushbroomImaging Radiometer (MPIR) instrumentand the CERES helicopter. These werecompared with BRDFs derived fromGeostationary Operational EnvironmentalSatellite (GOES) data (at the TOA). RMSdifferences (comparing angular bins) weregenerally between 15-30% for a solarzenith angle of 45°, and increased to 30-45% for a solar zenith of 75°. Surfacewetness was found to be an importantfactor.

Norman Loeb examined the anisotropy inCERES LW- and window-channel radi-ances as a function of cloud properties inovercast conditions over ocean. Whilelimb darkening was shown to increasedramatically with decreasing IR emissivity(especially in the window channel), therewas less sensitivity to cloud-top tempera-ture.

Bill Collins presented comparisons ofclear-sky TOA outgoing LW radiation(OLR) from three satellite Earth-radiationmissions with theoretical calculations.

Differences were shown to dependsystematically on column-mean relativehumidity (RH).

Richard Green (LaRC) led a discussion onthe definition of flux for CERES. It wasproposed that CERES radiance-to-fluxconversion be first performed relative to apixel’s location at the Earth’s surface, andthen adjusted to the TOA (defined at 30km) by applying a ~1% correction toaccount for the flux dependence on height.The question of whether a 30-km height isappropriate generated much discussion.

Time Interpolation and Spatial Averaging

(TISA) Working Group: David Young leddiscussions of software development,current temporal and spatial averagingstudies, ongoing CERES ERBE-likevalidation efforts, and the first resultsfrom the CERES enhanced temporalinterpolation algorithms using data fromgeostationary satellites. Maria Mitchum(LaRC) presented an overview of thestatus of the operational code for theseven TISA subsystems; all subsystemshave been delivered to the LangleyDistributed Active Archive Center(DAAC). Recent algorithm changesinclude the inclusion of overlap data and adata filter for striping in the geostationarydata. Near-term plans include geostation-ary satellite data inter-calibrations usingVIRS data, and modifications to handleCERES data from multiple instruments.Takmeng Wong (LaRC) presented atechnique for identifying and removingbad data records from the GOES-8 datafiles. This data filter, which compares themean and standard deviation of radiancesfrom consecutive scan lines, has beenincorporated into the operational code.Stéphanie Weckmann (VPI&SU) presenteda technique for removing the spatialresolution bias between monthly meanflux estimates from scanner and non-scanner measurements. The results show

that simulation of the non-scanner field-of-view with the higher resolutiongridded scanner data eliminates seasonalvariations in scanner/non-scannercorrelations. The working group discussedthe first results from Subsystem 10.Comparisons of monthly mean fluxesderived with and without the use ofgeostationary data were shown.

Investigator Presentation Highlights

Bryan Baum (LaRC) presented a tech-nique for identifying pixels in which a thinice cloud overlaps a thick water cloudusing data from the MODIS AirborneSimulator (MAS). The technique is basedon properties of water and ice cloudscomputed with a discrete-ordinate codeand uses measured reflectance at 1.63 µmand brightness temperature at 11 µm.

Don Cahoon (LaRC) presented resultsfrom the CERES ARM Radiation Experi-ment (CARE) conducted during August1998 at the ARM SGP site. Cahoon alsodescribed the CERES validation facilitybeing set up on the Chesapeake Light-house platform, about 25 km east ofVirginia Beach, VA, in the Atlantic ocean.This facility is expected to be operationalby August of 1999 and will be used tomonitor spectral SW radiation reflectedfrom the ocean surface.

Robert Cess (State University of NewYork at Stony Brook) presented results of astudy conducted by Meredith Croke, ahigh school student who worked with himlast summer. This study showed therelationships between the change in globalmean climate (represented by global meanTs) and cloudiness over three differentregions of the U.S., namely, the coastalsouthwest, the coastal northeast, and thesouthern plains. Cloudiness in all threeregions was found to increase withincreasing Ts. Cloudiness was also


9

correlated with other indices of regionalclimate.

Thomas Charlock (LaRC) presented anessay on detecting a climate-change signaland the importance of a continuous long-term record of broadband TOA ERB for itsdetection. He showed from the results of asimple 1-D radiative-convective modelthat, taking into account the heat taken upby the deep oceans, a substantial imbal-ance in global-annual TOA ERB isrequired to cause a warming trend. Heshowed further that the CERES instru-ment exhibits sufficient year-to-yearstability and precision to measure the TOAimbalance needed to produce a warmingtrend. Charlock stressed the need toproduce a long-term record of broadbandTOA radiation budget and identified it asa key resource for refining and validatingthe next generation of coupled atmo-sphere-ocean climate models.

Jim Coakley (Oregon State University)gave a progress report on his new pixel-level cloud-retrieval studies. He isidentifying techniques for extracting cloudinformation from clusters of fairlyhomogeneous cloud pixels in order toassist in deriving cloud properties forindividual pixels.

Leo Donner (NOAA/GFDL) presentedresults of a General Circulation Modelexperiment in which a mesoscale compo-nent using vertical convective velocities,in addition to the mass fluxes, was addedto the cumulus parameterization of themodel. He suggested that the currentparameterizations do not predict the iceformation and also miss the large radiativeforcing associated with cumulus convec-tion. Donner showed that the newparameterization is based on more explicittreatment of mesoscale processes. It needsless frequent and less penetrative convec-tion to produce cumulus clouds. The

resulting clouds exhibit more realisticmicrophysics and cloud-radiation interac-tions.

Alexander Ignatov (representing LarryStowe, NOAA/NESDIS) presented resultsfrom continuing work on retrieval ofaerosol properties from VIRS pixel-leveldata and current SSF product. Theiralgorithms retrieve aerosol propertiesfrom VIRS radiances in channels 1 and 2(0.63 µm and 1.6 µm, respectively). Heshowed size distribution, Angstromexponent, and the dependence of aerosoloptical depth (AOD) on solar and viewingzenith angles.

Robert Kandel (LMD France) presented abrief overview of the TOA ERB measure-ments obtained during the last 25 yearsand examined the data looking for climatetrends. He examined zonal mean OLR forthe 40°N-to-40°S band averaged for mid-seasonal months over several yearsobtained from ERBE, ScaRaB, and CERES.He also examined the tropical means(averaged over 20°N-to-20°S) for SW andLW radiation looking for trends. Hepointed to much variability within thesystem on regional scales but a weaktrend, if any, on the global scale.

Bing Lin (HU) presented estimates ofturbulent heat fluxes over tropical oceansderived from TRMM data. He summa-rized earlier work on the retrieval ofturbulent heat fluxes and showed thatretrievals from TRMM Microwave Imager(TMI) data have a much higher accuracy.

V. Ramanathan (Scripps Institution ofOceanography) presented an outline of astudy of water vapor greenhouse effect(G) to be based on CERES data. Based onearlier work, he showed that the clear-skyvalue of G for the mid-latitude summeratmosphere was about 130 Wm-2, which ismuch larger than for any other constituent

of the atmosphere. Ramanathan showedfurther that the weighting function for Gis distributed uniformly throughout thetroposphere, and that water vaporfeedback on G was always positivecontrary to Lindzen’s hypothesis.

David Randall (Colorado State Univer-sity) presented early results from afuturistic climate model which is alsoeasily compatible with CERES data. It is afinite-difference model in which all except12 grid boxes are hexagons (the remaining12 are pentagons). The spatial resolutionof this model is roughly equivalent to theT42 resolution of the Community ClimateModel (CCM3). A very attractive featureof this model is its quasi-isotropic geom-etry, i.e., grid boxes share walls with allneighboring boxes. This feature results inbetter performance by the model in thepolar regions.

Shi-Keng Yang (representing Jim Miller,NOAA/National Centers for Environmen-tal Prediction, NCEP) presented results ofan examination of the radiation moduleused in the current version of the NCEPdata assimilation model. The modelyielded about 10-20 Wm-2 higher OLRover the tropical Pacific ocean whencompared with ERBE results. He attrib-uted this discrepancy to the very lowvalues of upper tropospheric humidityfound in the model.

Science Team Logistics

The next CERES Science Team meeting isscheduled for early December 1999 at theNASA Langley Research Center. The focuswill be threefold: the progress of valida-tion for clouds, ADMs, SARB, and TISA,new science results from the science team,and an examination of the first resultsfrom CERES on Terra.


10

The complete set of these minutes andattachments is available in PortableDocument Format (PDF) on the MODISMeetings Page at http://modarch.gsfc.nasa.gov/MODIS/SCITEAM/minutes.html.

Introduction

The MODIS Science Team meeting washeld May 3–6 at the Greenbelt Marriottnear Goddard Space Flight Center (GSFC).Vince Salomonson welcomed participantsand said the meeting would focus on dataproducts and algorithms. He suggestedthat a Terra meeting at the launch mightbe held in California to coincide with thelaunch of the Terra spacecraft, with theMODIS Protoflight Model (PFM) instru-ment on board.

Terra Project Status

Kevin Grady stated that three majorreviews of the Terra spacecraft, the pre-ship, launch-vehicle readiness, and flightoperations reviews, took place in April.Planned pre-launch activities include finalspacecraft testing, propellant loading, andspacecraft closeouts. Remaining liensinclude demonstration of the operationalreadiness of all ground systems and a

Moderate Resolution ImagingSpectroradiometer (MODIS) ScienceTeam Meeting Summary

— Mike Heney and Deborah Howard([email protected])Science Systems and Applications, Inc.

possibility that the recent Centauranomaly during a Titan IV launch couldimpact Terra’s launch. Grady reported thatthe spacecraft and instruments are readyfor launch.

MODIS Sensor Status

Bruce Guenther presented a comparison ofLevel 1B (L1B) products with MODIS PFMinstrument specifications. The electricalcrosstalk on the instrument has beenmitigated, with residual effects to beevaluated on orbit. Guenther presented asummary chart on the status of L1Bparameters on a band-by-band basis; itwill be maintained on the MODIS Charac-terization Support Team’s (MCST’s)Website. He reviewed the instrumentactivation sequence, identifying guidingobjectives and providing major mile-stones.

MODIS Level 1A and GeolocationStatus

Jeff Blanchette provided a status report onMODIS Level 1A (L1A) and geolocationcode. Product Generation Executive (PGE)01 was delivered in March, land control-point matching software has been devel-oped, and island control-point software

delivery is planned for July 1999.Blanchette reviewed the GeolocationVersion 2.1 (at-launch) schedule. Version2.2 will be worked on post-launch, andwill include MODIS metadata and arobust G-ring algorithm.

MODIS L1B Readiness andSoftware Plans

Bruce Guenther provided an overview ofMODIS L1B software readiness and plansfor updates. He said that the currentversion, 2.1.5, incorporates all scienceupdates received through March 1999. Thenext delivery, due at the end of May,includes many enhancements such assaturation fixes, a revised thermal-bandlook-up table, a refined uncertaintyalgorithm, and minor code fixes. Guentherpresented the post-launch, L1B timelinethat includes rapid-response changes, low-to-moderate-impact changes, and frequentlook-up table updates resulting fromcalibration and characterization activities.Computer Resources of MCST (CROM)will likely develop and implement theseupdates.

Goddard DAAC Status forProduction

Steve Kempler reviewed the status of theGoddard DAAC (GDAAC) ingest andproduction processing of MODIS data. Heoutlined the projected at-launch data flowand discussed the current system status.The GDAAC is conducting a series ofOperational Readiness Exercises (OREs) toevaluate the system’s functionality andperformance. Kempler reported on thestatus of the Science Software Integrationand Test (SSIT) system. Some manualintervention still is required for processesthat should run automatically. Themitigation approach includes working onfixes to the automated system, document-ing the interim manual process, andtraining operators.


11

MODAPS Status for Production andDistribution

Ed Masuoka reported on the status of theMODIS Adaptive Processing System(MODAPS) for production and distribu-tion of MODIS Level 2, 2G, and 3 sciencedata products. He said that the ingestportion of the Science InvestigatorProcessing System (SIPS) interface worksand that MODAPS is able to receive andingest L1 products from the GDAAC.Masuoka reviewed open items, includingEarth Science Data Type (ESDT) filemismatches, network bandwidth issues,and complete SIPS delivery. He discussedthe status of at-launch PGEs, reported onn-day test results and provided a schedulefor integration into the at-launchMODAPS system. He also outlined theQuality Assurance (QA) and Validationresources. A suite of software packagesand some workstations are available forvalidation work onsite at GSFC.

GDAAC Archiving and Distributionof MODIS Data

Steve Kempler provided an update on theMODIS Oceans and Atmospheres dataarchiving and distribution by the GDAAC.The EROS Data Center (EDC) will processland data. He reviewed at-launch dataflows and current operational status oflaunch-critical capabilities. The groupdiscussed how to respond to the expecteddemand for early MODIS data products.Suggestions included producing datasamplers to allow the user community tofamiliarize themselves with MODIS dataand how to use it, and posting informa-tion on data product availability atconferences and in publications.

New Millennium Red Eye Proposal

Dennis Chesters notified the MODISScience Team of a proposed project toobtain Landsat 7-like datasets from

geosynchronous altitude, Red Eye. Thiswill be proposed as a New Millenniumproject.

EDC Status for Archiving andDistribution

Brad Reed discussed the EDC status forMODIS Land data archiving and distribu-tion. Full-up system tests will begin afterthe SIPS interface becomes available withEOS Core System (ECS) Version 5A. Datainitially will be distributed to the publicvia File Transfer Protocol (ftp) and 8-mmtape. The ECS Version 5B release also willsupport distribution via CD. Issues to beresolved include data release approval,release scheduling, and questions of datavisibility.

NSIDC Status for Archiving andDistribution

Greg Scharfen reviewed the NationalSnow and Ice Data Center (NSIDC) statusfor archiving and distributing Level 2 and3 snow and ice data products. ECS Version4PY is running in all three modes; version5A is expected in June. NSIDC success-fully participated in the Terra End-to-EndScience System (TESS) test. Acceptancetesting is ongoing, and participation inupcoming E-T-E and ground-system testsis planned. NSIDC will provide polar-gridded products at launch, with produc-tion volume dependent on MODAPSresources. Issues in work include thepreparation of a draft operations agree-ment and an upcoming review of the SIPS-ECS Interface Control Document (ICD).

MODIS Routine Operations

Bruce Guenther presented the MODISroutine operations plan. A Field CampaignForm is available on the MCST Web site;code and look-up tables will be availablevia e-mail subscription. Calibration/Validation Workshops are planned and a

set of Calibration-Applicable Archive TestScenes (CAATS) will be used to test theimpacts of calibration changes on Level 2products. MCST envisions good commu-nications with the user community. Level1B data and code will be widely available,and the MCST Web pages will provideinformation describing the L1B products,calibration, and change histories.

Validation and Geolocation

Robert Wolfe described the MODISGeolocation Validation and OperationalQA plans. The geolocation processinvolves instrument characterization,ground control-point matching, erroranalysis, and production software modelupdates. The long-term focus will be onmonitoring the stability of instrumentgeometric parameters and refining thegeometric characterization of the instru-ment. Wolfe said that geolocation isrelative to Band 0, and that band-to-bandregistration information is measured byMCST.

Validation and Operational QA ofL1B

Bruce Guenther summarized plannedvalidation and operational QA activitiesfor MODIS L1B products. Categoriesinclude 10 operational activities, 19calibration activities, and 19 vicariousactivities. These activities will be mappedinto radiometric, spectral, spatial, andother validation studies. Regarding QA,Guenther discussed converting radiomet-ric uncertainty into a 4 bit (0-15) scalingindex using an exponential scalingfunction. He reviewed the uncertaintyvalues corresponding to each index valueon a band-by-band basis and presented anoverview of L1B QA products.

L1B Radiance Validation

Kurt Thome discussed L1B radiancevalidation. He reviewed the validation


12

process and outlined the field calibrationplan that includes on-orbit instrumentcross calibration between field campaigns.He said that joint campaigns with othergroups would be welcome. The initial QAvolume is expected to be four or fivescenes over the first several months,ramping up to one scene per day asexperience is gained in collecting fielddata and in training students for fieldcampaign work.

Science System Status

Mike Moore of Earth Science Data andInformation System (ESDIS) provided aScience System status update. He said thatsince the last MODIS Science Teammeeting, the Flight Operations System(FOS) has been replaced by Raytheon’sEOS Mission Operations System (EMOS).He presented a list of the ECS Release 4 at-launch capabilities and reviewed ingestand archive issues being worked. Data-base configuration problems prevent sometypes of searches from working; patchesfor this are being developed. All funda-mental search, order, and distributionrequirements defined in the ECS baselinehave been verified.

Early Science and Science Outreach

Yoram Kaufman said the Terra outreachteam coordinates outreach activities of thePIs through the Executive Committee forScience Outreach (ECSO). David Herringadded that the team is establishing an EOSRapid Response Network and managingthe Earth Observatory web site. The RapidResponse Network headed by Jim Collatz,plans to foster rapid turn-around of Terraand Landsat 7 imagery over significantEarth events. They have a verbal agree-ment with the USGS Center for theIntegration of Natural Disaster Informa-tion (CINDI) to share information, andwill work to produce data visualizations

for release to the public media. Herringreviewed the Earth Observatory Web site,found at http://earthobservatory.nasa.gov. Other outreach activities include apartnership with the SmithsonianInstitution’s American History andNatural History museums, work with theLearning Channel on documentaries on”Fire” and ”Ice,” and publication ofarticles in popular magazines. Comple-mentary Web sites include the Terra pageat http://www.terra.nasa.gov and theGlobal Fire Monitoring site at http://modarch.gsfc.nasa.gov/fire_atlas.

MODIS Direct Broadcast Data Level1 Processing System Status

Daesoo Han reported on the status of theMODIS L1A and L1B Direct Broadcast(DB) system. MODIS direct broadcastingwill operate except when the spacecraft isin range of a Deep Space network station.Approximately 1 GB of data will beavailable per 10-to-12-minute overheadpass. The MODIS DB Ground Team(MDBGT) is providing the source codeneeded to produce Level 1 and a limitednumber of Level 2 products. The Release 1processing system has been tested and isready for release. Future work includesincorporating MODIS production softwarechanges and adding Level 2 products intothe DB system.

NOAA Plans

Gene Legg described NOAA’s plans forMODIS data. Their objective is to examineand determine the applicability of EOSPrototype Operational Instruments (POIs)to NOAA’s warning and forecastingobligations. NOAA is primarily interestedin data from the continental United Statesand its coastal waters, and will be produc-ing products that correspond to the first 10PGEs. Data products should be availablewithin 180 minutes of NOAA’s receipt ofLevel 0 data. MODIS data will be re-

viewed by NOAA data Product OversightPanels (POPs) with input from the MODISScience Team before release. Panelapproval will be required for the routinerelease of data products.

MODIS PFM/FM1 Status

Neil Therrien provided a status update forthe MODIS PFM and FM1 instruments.The PFM instrument is at the VandenbergAir Force Base (VAFB) launch facility, andMODIS test equipment is up and running.Spacecraft-level science checks for MODIShave been completed. A thermal vacuumretest is scheduled for mid-May, and theFM1 instrument completion is scheduledfor midsummer 1999. Guenther summa-rized the improvements of FM1 over PFM,including improved polarization measure-ments and scan-mirror-scatter quality, andthe reduction or elimination of light leaksin the system.

Oceans Products Status

Bob Evans reviewed the status of theOceans science products. Version 2.2delivery reduces the number of ESDTsfrom over 2000 to about 160. Sciencealgorithms have been updated, andprogram efficiency improvements havebeen made. In particular, improvementsmade to HDF file utilization resulted inreducing the amount of time spentreading the file from 60 minutes to about 1minute. The ability to make products nowfalls within the CPU resources that SDSTspecified; it is important to get the newVersion 2.2 software into the productionsystem. Evans is confident that the Oceansteam will be able to produce goodproducts at launch.

MODIS Science at the University ofWisconsin

Paul Menzel discussed the status ofMODIS science at the University of


13

Wisconsin. He reviewed updates to theMODIS cloud mask and summarizedcollaborative work with Zhengming Wanon surface emissivity and soundings.Menzel presented results from the March1999 Winter Exercise (WINTEX) fieldstudy and a MODIS Vicarious Calibrationcampaign over the Antarctic Plateau. It isexpected that Top of Atmosphere (TOA)accuracies in upwelling radiance overAntarctica should be on the order of 0.05K. He closed with a summary of MODISdirect broadcast capabilities at Wisconsin;the system should routinely be acquiringdata by the end of 1999.

Night-Time Band 36 MODIS Data

Jan-Peter Mueller presented a proposal fora new product, using night-time band 36data to quantify urbanization. Analysesindicate that MODIS should be able todetect night-time lights at higher spatialresolution and with better radiometriccalibration than is possible with theDefense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS). Mueller would like to use the night-time band 36 data early on to determinethe feasibility of producing new post-launch products. Guenther commentedthat taking one orbit’s worth of this dataevery other day should not overload thesystem, and that some night-time datacollections ordinarily would take place forSWIR calibration.

Oceans Summary

Wayne Esaias summarized the OceansBreakout sessions. He acknowledgedtremendous progress in the MODAPSsystem over the past 6 months andemphasized a need to integrate the Oceansproducts through Level 3 into the system.Esaias discussed validation plans thatinclude a validation cruise scheduled foroff the coast of Mexico from October 1–21.

A launch slip would result in no MODISoverflight data to validate. He describedplanned early science efforts that willfocus on iron limitation for ocean produc-tion, fluorescence efficiency, and regionalphenomena.

MODLAND Summary

Chris Justice summarized the MODLANDbreakout sessions. He noted that datasystem issues dominated the discussions.The Land group will continue prototypingQA data for the n-day test. He suggestedthat user services coordination is needed.An integrated land schedule has beendeveloped, combining the MODLANDproduction, QA, and Validation timelines.Justice presented a strawman proposal forLand early products and images, and helisted validation opportunities andresources. He said that closer links withother sensors are needed to perform cross-calibration, validation, and multisensorscience. MODLAND suggests an EarlyProducts meeting at about 6 months post-launch to focus on how users can obtaindata, product quality, and improvementsin the data. A Science Results meetingwould follow at about 12 months afterlaunch.

Atmospheres Summary

Michael King chaired the AtmospheresBreakout session. The group discussedmostly data processing and system issues,including the PGE update schedule.PGE55, Clear Sky Radiance (CSR), is stillbeing worked and may not be imple-mented at launch. This code takes clearscenes from cloud mask and writes the fileto granule. It is then integrated into thedaily global composite. Time series areused by cloud mask and cloud product tobetter determine the clear scenes. Al-though CSR would improve cloud mask,it can run without it. The group consid-

ered the contents for an Atmospheres Website. Suggestions included an overview ofproducts, links to product sites, calendar,staff listings, a bulletin board and imagevisualization tools, product imagery, andsome early sample designs. They talkedabout parameters for releasing data to thecommunity and how to get data outquickly and accurately.

Closing Remarks

Vince Salomonson closed the plenarysession, noting that all topics were well-covered by the discipline groups. He wasvery supportive and enthusiastic about anearly products meeting in the launch +6month timeframe. After announcing thenext meeting would take place near VAFBwithin 3 days of the Terra launch,Salomonson declared the meetingadjourned.


14

I. Introduction

The National Aeronautics and SpaceAdministration’s (NASA’s) Earth Observ-ing System (EOS) Project Science Officehas established a program in conjunctionwith the National Institute of Standardsand Technology (NIST) to validateradiance scales of sources at NASAcalibration facilities and to establishtraceability to national standards main-tained at NIST (Butler and Johnson 1996a,b; Butler and Barnes 1998). Under theauspices of this program, several portabletransfer radiometers have been built byNIST for NASA to measure radiance in thevisible (Johnson et al. 1998a), the short-wave infrared (Brown et al. 1998), and thethermal infrared (Rice and Johnson 1998)wavelength regions. The portable radiom-eters travel to EOS satellite instrumentbuilder facilities and EOS vicariouscalibration facilities in order to measurethe radiance of designated sources, oftenin conjunction with radiometers fromother U.S. and international laboratories.The results are then used to validate theradiance scales of the sources and to tiethese scales directly to the radiance scalemaintained by the national standardslaboratory.

A Portable Integrating Sphere Sourcefor Radiometric Calibrations from theVisible to the Short-Wave Infrared— Steven W. Brown ([email protected]), and B. Carol Johnson, National Institute of

Standards and Technology, Optical Technology Division, Gaithersburg, MD

Transfer radiometers from variouslaboratories are often calibrated usingdifferent techniques. When they subse-quently measure the radiance of a source,results among the instruments vary byapproximately 2 % in the visible, increas-ing to greater than 5 % in the short-waveinfrared1. We would like to reduce thevariance in radiance measurements madewith the transfer radiometers. A portable,stable sphere source could be calibratedfor spectral radiance at NIST using theFacility for Automated Spectral Irradianceand Radiance Calibrations (FASCAL), thefundamental U.S. facility for radiancecalibrations (Walker et al. 1987). Measur-ing this source with transfer radiometersfrom NIST and other institutions wouldvalidate their radiance responsivity scalesand tie them to the national radiance scalemaintained at NIST. Using this approach,problems in the radiance responsivitycalibrations of the field instruments couldpotentially be identified and the variabil-ity in radiance measurements usingdifferent instruments reduced.

Many of the transfer radiometers are filter-based instruments, with filter centerwavelengths and bandpasses selected fora specific application, such as for calibra-

tions of sources associated with a particu-lar flight instrument (Johnson et al. 1998a).This type of transfer radiometer canmeasure the radiance of a source at afinite, limited number of wavelengthswith fixed bandpasses. The sourceradiance at other wavelengths — oftenimportant for the calibration facility — isthen calculated by interpolation betweenthe radiometer fixed wavelengths. Theaccuracy of the sphere radiance atintermediate wavelengths derived fromfilter radiometer measurements thereforedepends, in part, on the validity of theinterpolation scheme. A stable field sourcecould in principle be used at the calibra-tion facility to validate the radiance of atarget source at any wavelength, as long assuitable radiometers were available.

To address these issues, we have designedand built a stable, portable, integratingsphere source. Similar in principle to theSeaWiFS Quality Monitor (Johnson et al.1998 b), the source was designed to beused at EOS calibration facilities inconjunction with the transfer radiometersover the wavelength range from 400 nm to2500 nm. Deployment of the source givesus extra flexibility in implementing theEOS radiance validation program. We arenow able to include source-based sphereradiance validation measurements inaddition to previously establisheddetector-based methods. In this applica-tion, it is important that the sphere sourcemaintain a radiance scale traceable toFASCAL in the field. While the monitordetectors provide a measure of thestability of the sphere output over alimited wavelength range, the truestability of the sphere output must bemeasured at several wavelengths over thespectral range of interest to verify thesource radiance stability. Optimal use ofthe source will therefore require that areliable, stable, well-characterizedradiometer accompany the source to a1 Butler, James J., NASA Goddard Space Flight Center, private communication.


15

particular field site and verify that itsradiance did not change upon shipping orupon use in the field.

In its first application, the sphere sourcewas shipped to a field site in Honolulu,Hawaii in support of the Marine OpticalBuoy (MOBY) program (Clark et al. 1997).These programs provide in situ measure-ments of water-leaving radiance forcomparison to satellite-derived results.This paper presents a description of theinstrument and results of stabilitymeasurements of the source radiance bothprior to and after its initial deployment.

II. Description

The sphere is 30.5 cm in diameter, with a10.2 cm exit aperture. Spectralon2 waschosen for the sphere walls for higherthroughput in the short-wave infrared andfor stability during shipping. The spherecomes equipped with four, 30-watt,quartz-halogen lamps located at 90-degreeintervals around the surface. Baffles areplaced between the lamps and the exitaperture of the sphere. Two monitorphotodiodes are placed near the bottom ofthe sphere. The first is a silicon (Si)photodiode equipped with a photopicfilter; the second is an indium galliumarsenide (InGaAs) photodiode equippedwith a 200-nm bandpass filter centered at1400 nm. The lamps are wired in series.Each lamp can be individually turned onor off during operation; timers record thetotal number of operational hours on eachlamp.

There are two modules associated with theportable sphere source, as shown in Fig. 1.The integrating sphere source and aninterface electronics box are located in the

upper module. The lower module containsa second interface electronics box, twodigital-to-analog converters (DACs), twocalibrated shunt resistors, two digitalmultimeters (DMMs) and two powersupplies. The second shunt resistor, digitalmultimeter and power supply areredundant; they are included as a safetybackup measure. However, they are alsodesigned to be used with standardirradiance lamps. This provides anadditional source capability with theinstrument for irradiance calibrations and,when used in conjunction with a referenceplaque, radiance calibrations.

Lamp connections, timers, ON/OFFswitches and photodiode amplifiers areincluded in the top electronics box. Thebottom electronics box supplies power tothe source and receives the lamp voltageand photodiode signals from the top box.These signals are then input into a DMM,and read into a computer through theGeneral Purpose Interface Bus (GPIB)

interface. In addition, the current to thelamps is monitored by recording thevoltage drop across a calibrated shuntresistor. This signal is also input into theDMM and recorded on a computer. Thecurrent to the lamps, the voltage dropacross each lamp, and the two photodiodesignals are automatically recorded in adata file every 10 s, along with the time,whenever the source is turned on.

The source can be operated in two modes,either passively or actively. In the passivecontrol mode, the power supply current isset through the GPIB bus and subse-quently monitored for stability. In theactive control mode, the power supplycurrent is remotely controlled by anexternal voltage. In this mode, the voltageto the power supply is continuouslyupdated to maintain a constant voltagedrop across the calibrated shunt resistor,thus stabilizing the current supplied to thelamps. The two twelve-bit DACs and avoltage divider provide the controlvoltage to the power supply. The totalresolution of the external voltage controlsignal is greater than 16 bits, enabling thecurrent from the power supply to be setwith very high precision. At the moment,the source is operated under passivecontrol.

III. Operation

The sphere radiance, measured with theVisible Transfer Radiometer (VXR), isshown in Fig. 2 for lamp combinationsranging from all lamps on to one lamp on.The data are given by symbols; the solidlines are cubic spline fits to those data.One of the primary functions of themeasurement assurance program is tovalidate measurements made by calibra-tion laboratories involved in calibratingthe spectral response of sensors developedas part of EOS. We designed the sphereradiance to be comparable to radiance

2 Identification of commercial equipment does not imply recommendation or endorsement by the NationalInstitute of Standards and Technology, nor does it imply that the equipment identified is necessarily the bestavailable for the purpose.

Lamp 1 Lamp 2

Lamp 3 Lamp 4

PD 1 PD 2

DAC

Control Box

Shunt Resistors

DMM 1 DMM 2

Power Supply 1

Power Supply 2

Fig. 1. Schematicdiagram of theportable integratingsphere source. PD1and PD2 refer to the Siand InGaAs monitorphotodiodes,respectively.


16

levels of those calibration sources. For example, the dottedline in Fig. 2 is the maximum level radiance from thesphere source at Raytheon Santa Barbara Remote Sensing.This source was used to calibrate the radiance responsivityof the Moderate Resolution Imaging Spectroradiometer(MODIS), currently scheduled to be launched on Terra(formerly AM-1), the first of several satellites to be de-ployed over the 18-year life of the EOS mission.

In Fig. 3, we show the operational characteristics of thesource over the course of an hour as lamps were graduallyturned off. Single lamps were turned off after 20 min, 31min, and 42 min. In Fig. 3 (a), we show the change in lampcurrent, measured as a voltage drop across the calibratedshunt resistor. With the exception of small changes of shortduration (shown by the arrows), the lamp current wasstable as lamps were turned off. The lamp current de-creased by approximately 0.03 % over the first 10 min ofoperation, then continued to decrease slightly (on the orderof 0.01 %) over the next 50 min.

The two monitor photodiode signals — shown in Figs. 3 (b)and (c) — showed very different behaviors. The Si monitorphotodiode signal was several times more stable than theIGA monitor photodiode signal. The Si monitor photodiodesignal changed on the order of 0.5 % over the first 20 min(four-lamp level), then remained stable to within 0.1 % overthe next 40 min (Fig. 3 (b)). On the other hand, over the first20 min (4 lamp level), the InGaAs monitor photodiodesignal changed by over 2 % (Fig. 3 (c)). As the second andthird lamps were turned off, the InGaAs signal continued

0.0000

50.000

100.00

150.00

200.00

300 400 500 600 700 800 900 1000

Four Lamps

Three Lamps

Two Lamps

One Lamp

SBRS Source

Radia

nce [µ

W/c

m2/s

r/nm

]

Wavelength [nm]

Fig. 2. Sphere radiance measured with the VXR for all four lamp levels.The dashed line is the maximum radiance of the SBRS source used tocalibrate MODIS.

-0.010

0.0

0.010

0.020

0.030

0.040

0.050

La

mp

Cu

rre

nt C

ha

ng

e [%

]

Lamp Off

-0.40

-0.20

0.0

0.20

0.40

Si M

on

ito

r S

ign

al C

ha

ng

e [

%]

-1.0

-0.50

0.0

0.50

0:00 10:00 20:00 30:00 40:00 50:00 60:00

InG

aA

s M

on

ito

r C

ha

ng

e [

%]

Elapsed Time [min]

(a)

(c)

(b)

Fig. 3. Change in (a) the lamp current, (b) the Si monitor photodiode signal, and (c) theInGaAs monitor photodiode signal over the course of an hour as individual lamps wereturned off. (�) Four lamp level; (o) three lamp level; (�) two lamp level; (∆) one lamplevel. The Si and InGaAs photodiode signals were normalized to their values at the endof each lamp sequence.


17

to increase with time: approximately 0.5 %over the next 10 min (3 lamp level), and0.3 % for the following 10 min (2 lamplevel). During the next 10 min (1 lamplevel) the signal decreased on the order of0.4 %. Because the radiant power emittedfrom quartz-halogen lamps is typicallyless sensitive to changes in the lampcurrent in the short-wave infrared than inthe visible or ultraviolet wavelengthranges, they are often more stable in theshort-wave infrared than in the visible(Early and Thompson 1996). Conse-quently, these results may indicate astability problem with the InGaAs monitordetector rather than an instability in thesphere output in the short-wave infrared.

To verify this hypothesis, we measured thesphere radiance at 1500 nm (4-lamp level)with the Short-Wave Infrared TransferRadiometer (SWIXR) (Brown et al. 1998)and compared the results with the InGaAsmonitor data. After a 10 min warm-up, theInGaAs monitor signal increased by 0.6 %over the subsequent 5 mins, while theSWIXR signal increased by 0.06 %. Onesource of instability in the InGaAs monitorsignal was thought to be the filter selec-tion. We had a filter in front of the InGaAsphotodiode that included the 1380 nmwavelength region – a known wavelengthregion of instability in sphere sourcesarising from water absorption in thesphere. The filter was replaced with onecentered at a wavelength of 1540 nm, witha FWHM bandwidth of 20 nm. Themeasurements were then repeated, and, asexpected, the change in the InGaAsmonitor diode signal decreased — by afactor of three. The signal change remainslarger than expected, however, andadditional work is required to identify the

source of the instability in the InGaAsmonitor diode output.

The VXR measured the sphere radiancecontinuously for 5 min for each lamplevel, starting at elapsed times of 15 min (4lamp level), 25 min (3 lamp level), 36 min(2 lamp level), and 47 min (1 lamp level).The data from all six channels showedsimilar trends over the five-minuteacquisition times. As expected, the spherewas more stable at longer wavelengths.This is illustrated in Fig. 4 for lamp levelsthree and four; the standard deviation ofthe individual radiance measurementscontinuously decreased as the measure-ment wavelength increased.

As discussed in Early and Thompson(1996), changes in the lamp current arereflected in the sphere radiance. The slightchanges in the lamp current shown in Fig.3 (a) are also seen in the Si monitorphotodiode signal (Fig. 3 (b)) and in theVXR measurements. Consequently, theslight temporal variations in the currentsupplied to the lamps contribute touncertainties in the sphere radiance. Sincewe are currently operating the system inthe passive mode, the short-term fluctua-tions in the sphere radiance can poten-tially be reduced through active control of

the current to the lamps. However, relativeuncertainties on the order of 0.05 % or less(Fig. 4) are much less than the uncertaintyin the sphere radiance as determined byFASCAL3 (Barnes et al. 1998), and muchless than the uncertainties currentlyrequired for EOS sensors such as MODIS(Barnes et al. 1998). Thus, an additionalradiance uncertainty on the order of 0.05% or less arising from slight changes in thecurrent supplied to the lamps will notnoticeably increase the overall uncertaintyof the sphere radiance. Based on themeasurements of the voltage drop acrossthe shunt resistor and the Si monitordiode, a 10-min warm-up time prior todata acquisition is sufficient for mostapplications.

To determine the repeatability of theinstrument, the sphere radiance was firstmeasured with the VXR (for all fourlevels); then the system was turned off.After a short wait, the system was turnedback on and the radiance again measured.The VXR remained stationary duringthese measurements. The sphere radiancerepeated for all lamp levels to within0.1 %; for most levels, the radiance valuesagreed with each other to within 0.05 %.To test the system reproducibility, theradiance was measured with the VXR one

0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

400 500 600 700 800 900

Four Lamp Level

Three Lamp Level

Sta

ndard

Devia

tion [%

]

Wavelength [nm]

Fig. 4. Standard deviationof measurements of thesphere radiance at sixwavelengths taken withthe VXR for the four-lamplevel and the three-lamplevel. The acquisition timewas 5 min for eachchannel.

3 The expanded uncertainties (k=2) in spectralradiance for this type of sphere source measured byFASCAL is approximately 1 % at 400 nm,decreasing to 0.5 % at 900 nm.


18

day, and the system turned off. The spheresource and the VXR were subsequentlymoved to a different location. Thefollowing day, the instrumentation wasturned on, the VXR again aligned tomeasure the central region of the sphereaperture, and the sphere radiance mea-sured. As shown in Fig. 5, the sphereradiance measured on the two subsequentdays repeated to within approximately0.1%.

Based on these measurements, weconcluded that the system was stable andthe radiance reproducible in the shortterm. We next wanted to test the stabilityof the source upon shipping the instru-ment to the MOBY field site. The sphereradiance was measured by the VXR priorto shipping and immediately upon itsreturn to NIST.

The calibration facility at the MOBY site isnot sealed from the atmosphere, andmeasurements were often made aftersunset. During the measurements, anumber of small bugs entered the sphereand thereupon expired — most likely fromthe extreme thermal environment theyencountered. Upon return to NIST, thosebugs remained in the bottom of thesphere. The VXR initially measured thesphere radiance with the bugs remainingin the sphere. The sphere was thencarefully and literally debugged, and theradiance again measured. As shown in theinsert in Fig. 6, the bugs caused a slightdecrease in the sphere radiance – approxi-mately 0.5 % from 600 nm to 900 nm,increasing to 0.75 % at 411 nm. Afterdebugging, sphere radiance measure-ments before and after the MOBY site visitagreed on average to within 0.05 % for theVXR channels ranging from 440 nm to 780nm (Fig. 6). At 411 nm, the sphere radiancemeasured after MOBY had decreased byapproximately 0.5 % over the radiancemeasured prior to the site visit, while at

870 nm the average sphere radiance hadincreased by 0.2 %. For comparison, thesilicon monitor photodiode signal for thefour lamp levels changed by –0.15 %, -0.23 %,+0.11 %, and +0.06 %, respectively. Thesedata correlate well with changes in thesphere radiance measured by the VXR at550 nm.

IV. Summary

In summary, we have developed aportable integrating sphere source tocomplement existing measurement

capabilities used to validate the radianceof sources at EOS calibration facilities. Thesource was designed to operate in theradiance range used to calibrate EOSsatellite sensors such as MODIS. At 550nm, for example, the source radianceranges from approximately 50 µW/cm2/sr/nm at the four-lamp level down toapproximately 10 µW/cm2/sr/nm for theone-lamp level. The source radiance isrepeatable to within 0.1 % in the shortterm. After shipping the instrument toHawaii, using it in the field, shipping itback and debugging it, the sphere

0.99850

0.99900

0.99950

1.0000

1.0005

1.0010

1.0015

1.0020

1.0025

400 500 600 700 800 900

Four Lamps

Three Lamps

Two Lamps

One Lamp

RadianceRatio[A/B]

Wavelength [nm]

0.9960

0.9980

1.000

1.002

1.004

1.006

1.008

400 500 600 700 800 900

Ra

dia

nce

Ra

tio

[B

efo

re/A

fte

r M

OB

Y]

Wavelength [nm]

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

400 500 600 700 800 900

Change [%

]

Wavelength [nm]

Fig. 5. Ratio ofradiancemeasurements takenwith the VXR ontwo different days,A and B.

Fig. 6. Ratio ofsphere radiancemeasurements withthe VXR prior toand after(debugged) the tripto the MOBY fieldsite. Inset: Radiancechange upondebugging thesphere. (�) Fourlamp level; (o) threelamp level; (�) twolamp level; (∆) onelamp level.


19

radiance as measured by the VXR de-creased slightly — approximately 0.5 % —at 411 nm and increased slightly —approximately 0.2 % — at 870 nm. Theradiance did not noticeably change at theother measured wavelengths. The Simonitor diode seems to accurately reflectthe radiance level in the visible wave-length range, though it exhibits decreasedsensitivity to sphere radiance changes at411 nm and at 441 nm.

The InGaAs monitor diode is not stableenough for our measurement purposes,and it will be modified to improve thestability. Also, the sphere source’s radianceand operating characteristics in the short-wave infrared need to be evaluated, alongwith the radiance uniformity within theexit aperture. It is next scheduled to travelwith the portable transfer radiometers toNASA’s Ames Research Center to validatethe radiance of a sphere source used tocalibrate optical sensors that are deployedfrom aircraft, such as the MODIS AirborneSimulator (MAS) (King et al. 1986).

References

Barnes, W. L., T. S. Pagano, and V. V.Salomonson, 1998: Prelaunch characteris-tics of the Moderate Resolution ImagingSpectroradiometer (MODIS) on EOS-AM1.IEEE Trans. on Geoscience and Remote

Sensing, 36, 1088.

Brown, S. W., B. C. Johnson, and H. W.Yoon, 1998: Description of a portablespectroradiometer to validate EOSradiance scales in the short-wave infrared.The Earth Observer 10, 43.

Butler, J. J., and B. C. Johnson, 1996a:Organization and implementation ofcalibration in the Earth Observing System(EOS) Project - Part 1. The Earth Observer,

8(1), 22 - 27.

Butler, J. J., and B. C. Johnson, 1996b:Calibration in the Earth Observing System(EOS) project - Part 2: Implementation. The

Earth Observer, 8(2), 26 - 31.

Butler, J. J., and R. A. Barnes, 1998:Calibration strategy for the Earth Observ-ing System (EOS)-AM1 Platform. IEEE

Trans. on Geoscience and Remote Sensing, 36,1056.

Clark, D. K., H. R. Gordon, K. J. Voss, Y.Ge, W. Broenkow, and C. Trees, 1997:Validation of atmospheric correction overoceans. J. Geophys. Res., 102, 17 209.

Early, E. A., and E. A. Thompson, 1996:Irradiance of horizontal quartz-halogenstandard lamps. J. Res. Natl. Inst. Stand.

Technol., 101, 141.

Johnson, B. C., J. B. Fowler, and C. L.Cromer, 1998a: The SeaWiFS TransferRadiometer (SXR). NASA Tech Memo1998-206892, Vol. 1, S. B. Hooker and E. R.Firestone, Eds., NASA Goddard SpaceFlight Center, Greenbelt, MD, 58pp.

Johnson, B. C., P.-S. Shaw, S. B. Hooker,and D. Lynch, 1998b: Radiometric andengineering performance of the SeaWiFSQuality Monitor (SQM): A portable lightsource for field radiometers. J. Atmos. and

Oceanic Technol., 15, 1008.

King, M. D., M. G. Strange, P. Leone, andL. R. Blaine, 1986: Multiwavelengthscanning radiometer for airborne mea-surements of scattered radiation withinclouds. J. Atmos. and Oceanic Technol. 3,513.

Rice, J. P., and B. C. Johnson, 1998: TheNIST EOS thermal-infrared transferradiometer. Metrologia, 35, 505.

Walker, J. H., R. D. Saunders, and A. T.Hattenburg, 1987: Spectral RadianceCalibrations. NBS Special PublicationSP250-1, US Government Printing Office,Washington, DC.

Continued from page 3)

AMSR Science Team Meeting

Greenland. Further details about thiscampaign can be obtained from ProfessorGudmansen at [email protected]<mailto:[email protected]>.

Before adjourning, we briefly discussedAMSR-E public outreach. A web site and/or a brochure outlining the benefits of theAMSR-E data will be available shortly.

The next Joint AMSR Science teammeeting is planned for 6 and 7 July, inOklahoma City, Oklahoma.

Acronym list:AMR airborne microwave

radiometerAMSR advanced microwave-scanning

radiometer for ADEOS-IIAMSR-E advanced microwave-scanning

radiometer for EOSAMSS advanced multi-spectral scannerAVIRIS airborne visible and infrared

imaging spectrometerEOSD earth observation system

developmentGAME GEWEX Asian monsoon

experimentGEWEX global energy and water cycle

experimentGRASP Greenland Arctic Ocean shelf

projectGTS global telecommunications

systemIOP intense operating periodMICRORAD microwave radiometry

and remote sensing of theenvironment

NASDA national aeronautics andspace administration of Japan

PSR polarimetric scanningradiometer

SAR synthetic aperture radarSGP Southern great plainsSSM/I special sensor microwave/

imagerTMI TRMM microwave imagerTRMM tropical rainfall measuring

mission (U.S.-Japan)


20

The first post-selection PathfinderInstruments for Cloud and AerosolSpaceborne Observations-ClimatologieEtendue des Nuages et des Aerosols(PICASSO-CENA) science team meetingwas conducted at the Radisson Hotel inHampton, VA, on May 18-19. DaveWinker, the PICASSO-CENA PrincipalInvestigator (PI) from Langley ResearchCenter (LaRC), welcomed all participants,briefly reviewed the agenda, and notedthat all 21 PICASSO-CENA science teammembers were present.

[See related article by Winker on page 22]

Day 1Ann Carlson, the Acting Assistant Directorfor Atmospheric Sciences at LaRC, gave aspecial welcome to our French partnersand our CloudSat partners. Ann noted thehard work previously performed by thePICASSO-CENA proposal team thatresulted in the winning proposal and wasconfident that the same hard work wouldresult in a successful mission.

Jim Garvin, the ESSP Project Scientist atGoddard Space Flight Center (GSFC),delivered his perspective of the PICASSO-CENA mission. He stated that PICASSO-CENA offers revolutionary scienceassociated with the role of aerosols in theEarth’s radiation budget, and that our

The First PICASSO-CENA ScienceTeam Meeting MinutesMay 18-19, 1999

challenge will be to preserve the baselinemeasurements under the realities of space-hardware development. Speaking fromlessons learned about previous missions,he urged us to strategize early aboutscience relaxation and descope plans. Headvised the PICASSO-CENA science teamto re-examine the minimum sciencerequirements and consider relaxingspacecraft requirements before deselectingscience instruments or derating instru-ment performance. Jim stressed theimportance of developing calibration andvalidation strategies early in the program.He recommended defining aircraft and/orcorrelative spacecraft measurements assoon as possible. Because the ultimatedeliverable is valuable science data, earlyrelease of preliminary data is desirableand can assist in developing outreachgoals as well as implementing the Scienceand Data Analysis Program (SDAP). TheSDAP will set aside approximately 10% ofthe mission cost for peer-reviewedinvestigations using PICASSO-CENA dataproducts. Jim’s final thoughts were on thechallenges associated with the lasersystem in spite of the recent successfulbench testing. He encouraged an airbornesimulation of the PICASSO-CENA lidarperformance. He also offered strategies foroptimizing sampling versus instrumentlifetime. Bob Curran, the NASA Head-

quarters PICASSO-CENA point of contact,shared his excitement about the PICASSO-CENA mission and flying lidars in spacefor atmospheric remote sensing. He wasalso pleased to announce that PICASSO-CENA and CloudSat were targeted for a

dual launch scheduled early in 2003 tofly in formation with EOSPM-1. Lastly, he requested

support from the PICASSO-CENA team in convincing both

Congress and the general public ofthe importance of the PICASSO-CENA

mission by clarifying the importance ofthe measurements obtained.

Dave Winker stepped through the scienceportion of the proposal, beginning withthe mission concept, then proceeding tothe science objectives and requirementsflowdown. He presented examples ofLITE approaches and measurementswhere appropriate for clarification. Davediscussed the descope plan that waspresented in the proposal. He emphasizedthat we are not locked into the minimummission defined in the proposal, but thatwe do need to solidify the minimummission by the end of the calendar year.Dave provided a definition, an approach,and an example of the Vegetation CanopyLidar (VCL) Descope Options.

Debbie Carraway, the PICASSO-CENAProject Manager at LaRC, gave thePICASSO-CENA project overview andstatus. She pointed out the major mile-stones and their corresponding dates. Themost critical event is the Mission Confir-mation Review (MCR), scheduled for July2000. The MCR is basically the “go/no go”decision point of the mission. Debbiehighlighted the following two documentsas deliverables from the science team inFebruary 2000: “Descope Plan” and“Science and Mission RequirementsDocument (SMRD).” An example outlineof the VCL SMRD was presented.

— Lelia Vann ([email protected]),Acting PICASSO-CENA Science Manager,Langley Research Center


21

Pat McCormick, a PICASSO-CENA Co-Principal Investigator (Co-PI) fromHampton University (HU), gave anoverview of several specific HU activities:an International Science Advisory Panel(ISAP), algorithm implementation,outreach, and validation. Pat has estab-lished a 7-member ISAP to broadenscientific oversight, expand the usefulnessand application of the data products, andprovide a vehicle for broad internationalcollaboration. Dianne Robinson presenteda variety of activities being planned forthe outreach program. A sunphotometer,the graphing calculator, and a web-sitecontest were just a few suggested activitiesthat are being proposed.

Jacques Pelon, a PICASSO-CENA Co-PIfrom the Institut Pierre Simon Laplace inFrance, presented the French scienceorganization and activities. Currently,there are three focused working groups:Climate and Chemistry Modeling, CloudProperties and Climatology, and AerosolProperties and Climatology. Each workinggroup is led by one of the FrenchPICASSO-CENA science team members.Jacques presented future validation plansas well.

John Stadler, the PICASSO-CENA SystemsEngineer from LaRC, delivered themission overview including the instru-ment descriptions, payload overview,PROTEUS spacecraft bus, PICASSO-CENA satellite, formation-flying strategy,and the resource margins.

Mary Beth Wusk, the PICASSO-CENAMission Operations Manager from LaRC/G&A Technical Software, presented themission operations concept. The satelliteutilizes both the S-band and X-band forcommunications. The S-band is used forboth command and telemetry of space-craft and instrument critical data, and S-band data are transferred to NASA fourtimes a day. The X-band is used for the

science data telemetry and data aretransferred within 48 hours.

Chris Hostetler, a PICASSO-CENA Co-I atLaRC, presented the Aircraft ValidationUnit (AVU) objectives and status. TheAVU consists of an aircraft-based oxygenA-band spectrometer (ABS) and a lidar. Adecision on making the AVU polarizationsensitive or insensitive will be made bythe end of May from technical and costanalyses being conducted by Ball. Thenear-term schedule was shown andindicates data acquisition beginning inFebruary 2000, with data available tosupport the MCR in August 2000.

Dave Winker presented the data productscontained in the Step 2 proposal andtalked about utilizing Algorithm Theoreti-cal Basis Documents (ATBDs) to describethe algorithms, data handling andprocessing, software interfaces, andprocessing requirements used in generat-ing these data products. He compared asimple data flow from telemetry to Level 2products with that envisioned forPICASSO-CENA.

He also presented the science teamorganization and identified workinggroups for major retrieval algorithms. Theprimary working groups are: Lidar, A-Band Spectrometer (ABS)/Wide FieldCamera (WFC), Imaging Infrared Radiom-eter (IIR), and Fluxes. Other teams thatmight generate joint data products withthe PICASSO-CENA and CloudSat teamsare being considered. In addition, anoutline of a generic ATBD was provided.Each working group is responsible forgenerating its corresponding section of theATBD.

Chris Currey, the PICASSO-CENA ScienceData Manager at LaRC, presented the datamanagement system overview includingthe DAAC interface, system sizing,

organization, and near-term plans. Hestressed the importance of defininginterfaces early and working as a teamwith the science working groups, HU,mission operations, and the DAAC toreach common scientific goals. Chrisintroduced the spiral model concept of thesoftware development life cycle for sciencedata products. This concept uses anincremental build and test approach as therequirements are developed and vali-dated. The data-management schedulepresented showed operational coderunning on the DAAC by September 2002.

Bob Charlson, a PICASSO-CENA Co-Ifrom the University of Washington,restated the first PICASSO-CENA scienceobjective from the proposal and identifiedwhat type of information was needed toestimate direct aerosol “forcing” and itsuncertainty. He stated that there is a needto distinguish between natural andanthropogenic forcing. This can only bedone with a set of in situ aerosol measure-ments to yield the chemical composition,optical properties, and microphysicalproperties. He presented an example of anautocorrelation versus lag distance toobtain an indication of how often tosample and how close in situ measure-ments need to be to the mission measure-ments to be useful for estimating radiativeforcing. There is a tradeoff between spatialoffset and sampling duration that needs tobe characterized for adequate aerosolforcing determination.

Graeme Stephens, a PICASSO-CENA Co-Iand the CloudSat PI from the ColoradoState University, gave the CloudSatmission overview showing the tightformation flying with PICASSO-CENA forcoincident lidar-radar profile informationand coincident EOS PM-1 information for



22

1. Introduction

Current uncertainties in theeffects of clouds andaerosols on the Earthradiation budget limit ourunderstanding of theclimate system and thepotential for global climatechange. Pathfinder Instru-ments for Cloud andAerosol SpaceborneObservations - ClimatologieEtendue des Nuages et desAerosols (PICASSO-CENA)is a recently approvedsatellite mission withinNASA’s Earth SystemScience Pathfinder (ESSP)program which will addressthese uncertainties with aunique suite of active andpassive instruments.

[See also related article by Vann on page 20]

The Lidar In-space Technology Experi-ment (LITE) demonstrated the potentialbenefits of space lidar for studies of cloudsand aerosols (Winker et al., 1996).PICASSO-CENA builds on this experiencewith a payload consisting of a two-wavelength polarization-sensitive lidar, anoxygen A-band spectrometer (ABS), an

imaging infrared radiometer (IIR), and awide-field camera (WFC). Data from theseinstruments will be used to measure thevertical distributions of aerosols andclouds in the atmosphere, as well asoptical and physical properties of aerosolsand clouds which influence the Earthradiation budget.

Global Observations Of Aerosols AndClouds From Combined Lidar AndPassive Instruments To ImproveRadiation Budget And Climate Studies— David M. Winker ([email protected]), NASA Langley Research Center

PICASSO-CENA will be flown in forma-tion with the EOS PM satellite and withthe recently selected CloudSat to provide acomprehensive suite of coincidentmeasurements of atmospheric state,aerosol and cloud optical properties, andradiative fluxes. The mission will addresscritical uncertainties in the direct radiativeforcing of aerosols and clouds as well asaerosol influences on cloud radiativeproperties and cloud-climate radiationfeedbacks (Figure 1).

PICASSO-CENA is planned for a three-year mission, with launch in early 2003.PICASSO-CENA is being developedwithin the framework of a collaborationbetween NASA and CNES.

2. Science Objectives

Atmospheric aerosols directly affect theEarth’s energy balance by absorbing andscattering shortwave (SW) solar radiation,and by absorbing and emitting longwave(LW) infrared radiation. Aerosols indirectly

affect this balance by modifying thereflectance and lifetime of clouds throughtheir role as cloud condensation nuclei,but this indirect forcing is poorly quanti-fied. Unlike greenhouse gases, tropo-spheric aerosols are highly variable inspace and time due to variable sourcesand short atmospheric residence times.Thus their radiative effects are also highlyvariable. The uncertainties in these effectsmay be more than half the entire green-house gas effect, but of opposite sign(Kiehl and Brieglieb, 1993; Jones andSlingo, 1996).

Currently, aerosol forcing estimates arebased on calculations using chemicaltransport models (CTMs). Large uncer-tainties in the estimated direct aerosolforcing are due to the fact that many of theinput parameters are not well known.Additionally, there are no existing global

Figure 1. PICASSO-CENA flies in formation with EOS PM-1 toobtain greater value data than obtainable from either mission alone.In addition, the recently selected CloudSat will be flying in formationwith PICASSO-CENA which will greatly enhance the data collected.This unique 3-year coincident global set of data on aerosol and cloudproperties, radiative fluxes, and atmospheric state enables newobservationally based assessments of the radiative effects of aerosoland clouds. This information will greatly improve our ability topredict future climate change.


23

observations of aerosol direct forcing,aerosol properties, or aerosol sourcestrengths against which these modelestimates may be checked. Future EOSmissions include instruments which willimprove current satellite aerosol observa-tions. However, EOS capabilities are notsufficient to allow accurate, measurement-based estimates of aerosol direct forcing.Understanding the Earth radiation budgetrequires observations of radiative fluxes atthe top of the atmosphere (TOA), at thesurface of the Earth, and at levels withinthe atmosphere. Cloud imager and CERESbroadband radiation observations fromEOS PM will provide estimates of TOAfluxes to an accuracy approaching 1.5 W/m2 for monthly zonal and global means(Wielicki et al. 1995). However, uncertain-ties in estimates of mean radiative fluxesat the Earth’s surface will be much larger,primarily due to the limitations of passivesensors in characterizing the verticaldistribution of multilayer clouds.

Improved representations of cloudprocesses in models are also required inorder to decrease uncertainties in cloud-radiation interactions. The fundamentalproblem is in modeling the cloud feedbackloop. The largest uncertainties involve theuse of models to: (a) predict cloudproperties based on atmospheric state, and(b) to use these cloud properties tocalculate radiative-energy fluxes.

Nearly simultaneous observations of allthree parts of the cloud feedback loop arenecessary to accurately predict the futureimpact of greenhouse gases. Near-simultaneity is required because of theshort time scales and nonlinear relation-ships typical of cloud processes. Theability of cloud models to reproducefeedback physics cannot be adequatelytested with observations that aredecoupled in space and time.

3. Instruments

To address these issues in a cost-effectivemanner, a payload consisting of four co-aligned, nadir-viewing instruments hasbeen defined:

◊ A two-wavelength, polarization-sensitive lidar providing high-resolution vertical profiles of aerosoland cloud properties. The change inbackscatter with wavelength allows aclassification of aerosol size. Theratio of orthogonally polarizedcomponents of the 532-nm backscat-ter allows the identification of cloudice/water phase.

◊ An oxygen A-band Spectrometer(ABS) having sufficient spectralresolution (0.5 cm-1) to resolve theline structure of the oxygen A-band(centered at 765 nm). ABS spectracombined with lidar profile data arecombined to retrieve aerosol andcloud optical depth, aerosol absorp-tion, and cirrus asymmetry param-eter (Stephens and Heidinger, 1999).

◊ An Imaging Infrared Radiometer(IIR) providing calibrated radiancesat 10.5 µm and 12 µm over a 40-kmswath. These two wavelengths arechosen to optimize joint lidar/IIRretrievals of cirrus emissivity andparticle size.

◊ A Wide Field Camera (WFC) cover-ing the 620-nm-to-670-nm spectralregion providing images of a 25-kmswath with a spatial resolution of 125meters. The WFC provides meteoro-logical context and highly accuratespatial registration betweenPICASSO-CENA and EOS-PM.

The data products to be derived fromPICASSO-CENA are summarized in Table

1. Level 2b products involve morecomplex algorithms than Level 2a and willrequire a longer period of validation beforebeing made available for distribution.

Table 1. PICASSO-CENA science data products.

DataLevel Data Products

1 lidar browse images, calibratedlidar profiles, calibrated ABS andIIR radiances, uncalibrated WFCimages

2a lidar backscatter profiles, aerosoland cloud height/thickness, aerosolextinction profiles/optical depth,cloud extinction profiles/opticaldepth, cloud ice/water phase

2b aerosol single-scattering albedo ice-particle size, cloud-layer emissivity,cirrus asymmetry parameter,surface and atmospheric radiativefluxes

4. Observing Strategy

The PICASSO-CENA orbit was chosen toprovide space-time coincidence with EOSPM observations. EOS PM is in a sun-synchronous 705-km circular orbit with anascending node equatorial crossing time of13:30 local time. PICASSO-CENA will flyat the same altitude as EOS PM, and itsorbit will be maintained so that a point onthe ground will be observed by the twoplatforms within 6 min of each other.

The inclination of the PICASSO-CENAorbit differs slightly from that of EOS PM,so that over the course of the 3-yearmission, PICASSO-CENA will slowlyprecess across the viewing swath of AIRS,CERES, and MODIS. Coincident observa-tions—allowing an assessment of viewing-angle biases in EOS PM retrievals—will beobtained for all seasons and atmosphericconditions.


24

5. Measurement Objectives

5.1 Aerosols

The single most important advance thatPICASSO-CENA provides is a highsensitivity to aerosols, even over brightand heterogeneous land surfaces andunder other conditions which are difficultor impossible for passive sensors, such asabove clouds or beneath thin cirrus.

Lidar provides high sensitivity to aerosol,but retrievals of ta involve uncertainties onthe order of 30%. This is sufficientlyaccurate at low optical depths, but athigher optical depths (ta > 0.04) joint lidar-ABS retrievals provide a significantimprovement over the retrievals fromeither MODIS or from lidar alone.

Simultaneous observation of aerosolproperties by PICASSO-CENA and ofradiative fluxes and atmospheric statefrom EOS PM will provide direct measure-ments of aerosol forcing and the keyparameters that control it. PICASSO-CENA will provide: (1) vertical distribu-tion of aerosols; (2) two-wavelengthaerosol backscatter measurements forclassification of aerosol size; (3) aerosoloptical depth; (4) aerosol single-scatteralbedo; and (5) aerosol source strength, anessential input to CTMs used to assessaerosol radiative forcing.

Further, PICASSO-CENA will allowimproved assessments of aerosol indirectforcing through greatly improved aerosolmeasurements as well as by unambigu-ously distinguishing clouds embedded inan aerosol layer from those located aboveor below the layer.

5.2 Clouds

The spatial overlap of multilayered clouds—which comprise over half of all surfaceobservations—represents the largest

optically thin clouds as a function ofcloud properties.

◊ For the same amount of condensedwater, ice crystals and supercooledwater droplets alter radiative fluxesin significantly different ways. Lidardepolarization measurements willprovide the first spaceborne verticalprofiles of cloud-particle phase andimprove our understanding of theradiative influence of mixed-phaseclouds.

6. Summary

The comprehensive combined data set tobe acquired by PICASSO-CENA and EOSPM will allow fundamental scientificadvances in our understanding of thelinks between aerosols, clouds, andradiation necessary to accurately assessfuture climate change. Realizing thispotential will require careful coordinationwith supporting modeling and correlativemeasurement efforts.

7. References

Jones, A., and A. Slingo, 1996: Predictingcloud-droplet effective radius and indirectsulphate aerosol forcing using a generalcirculation model. Q. J. R. Meteor. Soc. 122,1573-1595.

Kaufman, Y. J., et al., 1997: Operationalremote sensing of tropospheric aerosolover land from EOS Moderate ResolutionImaging Spectrometer. J. Geophys. Res. 102,17051-17067.

Kiehl. J. T., and B. P. Brieglieb, 1993: Therelative roles of sulfate aerosols andgreenhouse gases in climate forcing.Science 260, 311-314.

NRC, 1996: A Plan for a Research Program on

Aerosol Radiative Forcing and Climate

Change. National Academy Press.

uncertainty in determining downward LWradiative fluxes at the surface and inestimating LW radiative heating in theatmosphere. Calculated heating ratesdiffer by as much as 30% of the typicalzonal-mean LW heating rate of -2 K/day,and the resulting uncertainties in regionalmonthly mean surface LW fluxes are ashigh as 20 W/m2. All current satellitecloud retrievals detect only an uppercloud layer or retrieve one equivalentcloud layer. Improved estimates of surfaceLW fluxes and atmospheric heating rateswill be obtained by combining CERESTOA flux measurements with coincidentobservations of multilayered clouds fromPICASSO-CENA.

Secondly, PICASSO-CENA provides newmeasurement capabilities which, whencombined with EOS PM observations, willallow a far more complete closure of thefeedback loop than possible using EOSPM alone. EOS PM will provide atmo-spheric state information and TOAradiative fluxes, and PICASSO-CENA willprovide coincident information on cloudaltitude, thickness, and optical andmicrophysical properties. These newmeasurement capabilities from PICASSO-CENA will enable significant progress inour understanding of cloud-radiationfeedback mechanisms:

◊ The first measurements of ice-cloudasymmetry parameter from acombination of the PICASSO-CENAlidar and ABS. These measurementswill provide critical information onthe relationship between cloudoptical depth and cloud reflectance.

◊ PICASSO-CENA observations ofoptically thin clouds such assubvisual cirrus and jet contrails willbe combined with simultaneousCERES TOA radiative fluxes toevaluate the radiative forcing of


25

Stephens, G. L., and A. K. Heidinger, 1999:Molecular line absorption in a scatteringatmosphere - Theory. (accepted, J. Atmos.

Sci.)

Tanre, D. et al., 1997: Remote sensing ofaerosol properties over oceans using the

(Continued from page 21)

The First PICASSO-CENA Science Team Meeting Minutes

unique overlap of data for studyingclouds. Graeme emphasized the need foridentifying joint activities early andsuggested organizing a “tiger team” nowto address these areas. Several areas forconsiderations are A-band redundancy,algorithm development, validation, etc.

He gave an A-band tutorial on the secondday. He stated that using absorbing andnon-absorbing bands within the A-band tomeasure the abundance of oxygen to infersurface pressure within a 0.5-mbaraccuracy has been done. He walkedthrough the clear-air problem and thenintroduced the atmospheric scatteringproblem. Graeme discussed the basicquestion of separating the atmosphericscattering from surface reflection. He alsointroduced the complexity of 3D effectsand addressed when 3D effects invalidatethe retrieval. Graeme provided two papersthat are to appear in Journal of the Atmo-

spheric Sciences (1999).

Deb Vane, the CloudSat Deputy PI fromJPL, presented some obvious discussiontopics for a dual launch, joint mission, andother science-related topics. She stressedthe importance of making a decision soonregarding the A-band instrument redun-dancy.

The second day began with presentationsof the retrieval algorithms for the Infrared

Imager Radiometer (IIR), the A-bandSpectrometer (ABS), and the lidar.

Jacques Pelon presented ice-crystal sizeand cirrus-effective-emissivity retrievalusing two IIR channels and a cirrusradiation scheme that uses the ratio of thetwo channels.

Dave Winker presented a top-levelschedule of the science team activities andhow they are phased to the missionmilestones. From this schedule, it becomesclear that preliminary algorithms need tobe defined and provided by each workinggroup for Level 1 and Level 2 productioncoding to begin by July 2000. As men-tioned previously, each working group isexpected to provide algorithms fromwhich production code can be written andtested.

He also proposed to submit a high-levelmission-concept paper to the Bulletin of the

American Meteorological Society (BAMS)this summer/fall and an instrumentpaper(s) to BAMS after the PDR in early2001. A technical splinter session withCloudSat and PICASSO-CENA projectpersonnel was held resulting in a numberof agreements, issues, and action items.The next (second) science team meetingwill be held this fall (the Novembertimeframe) and the third science teammeeting will be held next May or July.

The lidar working group leader, ChrisHostetler, provided an example of thetypes of activities that would be requiredof the lidar working group as a demon-stration of typical activities that may berequired of the other working groups. Theultimate deliverable from each workinggroup is an algorithm theoretical basisdocument (ATBD) from which the Level 1and Level 2 processing code can bedeveloped. A draft of the ATBD is targetedin support of the Preliminary DesignReview (PDR) that is currently scheduledfor June 2000.

Other related activities were presented byRay Hoff, Co-I from the University ofMaryland-Baltimore Campus, and by JimCoakley, Co-I from Oregon State Univer-sity. Ray Hoff utilized LITE backscatteringdata to compare with results from theNorthern Aerosol Regional Climate Model(NARCM). The model was not entirelycomplete, but preliminary results agreedquite well. Jim Coakley presented lessonslearned from the Indian Ocean Experi-ment (INDOEX).

MODIS/EOS spectral radiance. J. Geophys.

Res 102, 16971-16988.

Wielicki, B. A., et al., 1995: Mission toPlanet Earth - Role of clouds and radiationin climate. Bull. Amer. Meteor. Soc. 76, 2125-2153.

Winker, D. M., et al., 1996: An Overview ofLITE: NASA’s Lidar In-space TechnologyExperiment. Proc. IEEE 84, 164-180.


26

Summary of the Mini-SWAMP Meeting

— David Herring ([email protected]), Science Systems & Applications, Inc.— Yoram Kaufman, Terra Project Scientist, NASA Goddard Space Flight Center

The Science Working Group for theAM Platform (SWAMP) convenedtwice during the EOS-IWG, held June15-17 in Vail, CO. The purpose of these“mini-SWAMP” meetings was todiscuss the latest information regardingTerra’s (formerly EOS AM-1) launchtimeline and flight operations, as well astentative plans for the first public presen-tation of Terra images. The meetings werechaired by Yoram Kaufman, with DavidHerring taking the minutes.

The ASTER team reported that theJapanese Ministry of International Tradeand Industry (MITI) prefers to releaseASTER’s first images as soon as possibleafter it acquires data—within 27 to 40 daysafter launch. Earlier in the planningprocess, the Terra strategy was to wait andjointly release the first images from all fiveinstruments simultaneously during apress conference at NASA Headquarters70 to 80 days after launch. David Herringtook an action item to organize a follow-up teleconference with representativesfrom all instrument teams to discuss thisissue and agree upon a platform-widestrategy.

Kaufman said principal investigators mustsoon begin thinking about and organizingspecial issues in scientific journals focusedon the Terra mission research objectives.He asked the Terra instrument team

leaders to notifyhim within two weekswhich conferences and/or specialissues they plan to organize for the Terrateam. Kaufman stated that the specialissues/conferences could be discipline-specific, but that each should be open toall instrument teams. It was tentativelyagreed that Vince Salomonson wouldcoordinate an IGARSS special issue; AnneKahle would take the lead for AmericanGeological Society (AGS); and Jon Ransonwill coordinate Terra special issuesactivities to ensure that there is a goodbalance of events and informationexchange.

Regarding Terra flight operations,Francesco Bordi took an action item tosend to all instrument principal investiga-tors a recommended strategy for imple-menting on-orbit spacecraft maneuvers, aswell as an update on present plans formaneuvers based on the current launchdate. The Terra team members are to sendtheir comments to Bordi within two weeksafter receipt of his recommendations. JimDrummond proposed developing an

ongoing strategy for the routine exchangeof information with the instrument teamleaders and, in particular, providing themadvance warning of new events and/orplans that impact on-orbit operations inthe first 50 days after launch. Herring tookan action item to identify someone toroutinely send these updates to the teamleaders. Bruce Barkstrom took an actionitem to distribute an explanation of thebenefits from the three moonless maneu-vers and the need for three of them so thatthe Terra community may discuss thistopic at the next meeting.

Kaufman reported that, basedupon a request from the

EOS Interdiscipli-nary Sciencecommunity,

the Terra principalinvestigators will generate,

by mid-August, a Web site thatshares information on Terra’s dataproducts. This Web site should include thedetails regarding the initial 50-percentdata production, data products, validationplans, knowledge of accuracy, file struc-ture, etc. Once established, this site will beannounced to the EOS IWG listserv.


27

Introduction

In February of 1996, NASA’s Earth ScienceEnterprise (then Mission To Planet Earth)awarded to the College of San Mateo andNASA Ames Research Center a three-yeargrant for a project entitled, “ACTES: “AnAssociate of Arts in Community Collegesfor Training in Earth Science – Implement-ing a Pilot Program for Remote SensingAnalysis and Earth Science Applications.”The grant was made in response to anapplication by the College of San Mateoand NASA’s Ames Research Center withthe general objective of achieving acommunity college curriculum, credit forwhich would be transferable to seniorinstitutions and increase the use of datawhich had been accumulated by NASA’ssatellite and aircraft research programs.This program of study would be madeavailable through conventional means andwould make use of the Internet for bothinstruction and dissemination. Further-more, it was expected that the develop-ment of the curriculum would increaseinterest in Earth science careers amongstudents and increase the awareness ofNASA Earth science research and data inthe general science curriculum.

The project had a variety of objectives thatincluded:

An Associate of Arts in CommunityColleges for Training in Earth Science(ACTES) Project

◊ An AA degree program that wouldbe developed during the project withthe primary objective of integratingremotely sensed data into a widevariety of courses.

◊ The material developed would bemade available for use in othercommunity colleges. The materialwould be available in both print and“on-line” form to provide maximumaccess.

◊ College of San Mateo (CSM) wouldbecome a source of curricularmaterials for other communitycolleges.

◊ A laboratory for students would beput into place for testing and use ofmaterials developed under the grant.

◊ CSM would recruit students and testmaterials to be developed during theproject.

◊ CSM would disseminate informationabout the program and the availablematerials.

Development Methods and Timing

The first stage of development requiredthe establishing of a test laboratory withboth Macintosh and PC platforms. Withthe laboratory in place and teachingfacilities obtained, the next step was toobtain permission to develop a new“field” of instruction at the college. TheCollege’s Committee on Instructionconcurred in the creation of this new fieldof study, i.e., Earth Systems. The newdesignation, ESYS, was put in place withan application made to the stateChancellor’s office for it to be designated anew program. The Committee on Instruc-tion also gave support for the offering of aspecial class leading to the development ofa permanent introductory class in the newfield. With just minimal notice about theproject, ten students were enrolled in thefirst ESYS class at the college. Thisresponse occurred with just a briefmention of the class or program in theschedule of classes, since the program hadbeen established too late for regularplacement into the schedule and catalog.

This student response compares quite wellwith the experience of California StateUniversity (CSU) Monterey Bay in itsstartup program in remote sensing. Withthis experimental class, we were able totest some materials in a classroom setting.The full program of courses for the majorwas submitted to the Committee onInstruction in April 1997 and two newcourses were taught in the academic year1997-98.

The first phase of the Internet workinvolved establishing a homepage for theprogram and introducing the concept ofthe program through the Internet. A multi-page site (now more than 15 pages) is inplace and may be visited at the address:“http://www.smcccd.cc.ca.us/smcccd/csm/actes/actes.html”. Outlines of the

— Jay W. Skiles ([email protected]), Principal Investigator, SETI Institute,NASA Ames Research Center, Moffett Field, CA


28

classes were also mounted on the Internetsite in preparation for offering someelements of the major “on-line.” Addition-ally, information about the skill set andproposed matriculation models were alsomade available on line.

Courses and Major Completed

In the last year (1998-99), the group of fivecourses that is the heart of the major inEarth Systems was approved by thecollege Committee on Instruction. Themajor was also accepted and placed in thecatalog to be published for the academicyear 1999-2000. Coincident with thoseapprovals was the acceptance of three ofthe courses for Internet instruction. TheState of California requires separateapproval for “distance” learning courses,and this approval was obtained from theCommittee on Instruction. At this time thearticulation process was put into motionto ensure that the new courses would betransferable to nearby California StateUniversities. Discussions are ongoing withCSU Monterey Bay with its remote-sensing program and with other CSU’swith Geographic Information Systems(GIS) and Global Positioning Systems(GPS) programs. Presently, all courses aretransferable for regular college credit.

Products

As required, products of the program,curriculum modules, and other support-ing materials have been produced. Amongthem are:

1. A website for the ACTES programwith descriptions of the courses, skillsets, suggested matriculation models,and examples of student participa-tion.

2. An automated on-line counselingprogram which will be made

available to all community collegesas part of the dissemination ofmaterial. This program, written injava script, can be adapted for use byother colleges.

3. A graphic “concept map” wascreated as a guideline for develop-ment and dissemination.

4. A toolbox containing graphicspreadsheets with illustrations foruse in classroom instruction wasdeveloped. This toolbox is designedto be used with Microsoft Excel andis specifically organized to assiststudents in global geometry and avariety of geometric calculations.

5. A resource World Wide Web pagewith links and annotated bibliogra-phy was created.

6. Five course outlines and lessons weredeveloped:a. An introductory course in Earth

Systems (ESYS 100) completewith 15 instructional modulesfor use on-line or as assistance toclassroom instruction. Thismaterial may be easily adaptedby any community college foruse on-line. It is already in“html” encoded form for webmounting. The course introducesthe basic concepts of the study ofEarth Systems with emphasis onearth geometry, GIS, GPS, andremote sensing.

b. A course in visual representationof data complete with 15instructional modules for use on-line or as assistance to classroominstruction. This material may beeasily adapted by any commu-nity college for use on-line. It isin “html” encoded form for webmounting. The course introduces

the basic concepts of the study ofdata, data presentation, filetypes, and modes of visualrepresentation.

c. An introductory course inremote sensing complete with 18instructional modules for use on-line or as assistance to classroominstruction. This material alsomay be easily adapted by anycommunity college for use on-line. It is in “html” encoded formfor web mounting. The courseintroduces the basic concepts ofthe study of remote sensing, theelectro-magnetic spectrum,sensor devices and technology,and file storage and file types.

d. A course outline with exercisesfor in-class instruction of GISand GPS concepts and software.It was decided early on that thiswas an inappropriate class foron-line or web instruction due tothe expense and sophisticationof the software involved.Instead, the materials availablesuggest a methodology andresources necessary for instruc-tional development of thesubject.

e. A course outline for a summaryproject called the “practicum.”

The above materials in number six aboveare available on line at the ACTES web sitefor downloading after June 1, 1999. Theywill also be available soon on CD-ROM.

The Future

Experience with several of the courses hasled to the development of strategies forthe future. It seems clear at this stage thatthe coursework involving global position-ing and geographic information systems,now taught as a single course, needs to bedivided into two separate courses. A


29

In order to validate the Moderate Resolu-tion Imaging Spectroradiometer (MODIS)Land Surface Temperature (LST) algo-rithm and product, the MODIS LST groupat the University of California, SantaBarbara (UCSB), has worked with thethermal-infrared (TIR) instrumentation,methodology, and field measurementssince 1993. Six of the field campaignsconducted in 1995-1998 were supportedby the flights of the MODIS AirborneSimulator (MAS) (http://asapdata.arc.nasa.gov/ames_index.htmlgives information on the test sites andflight lines).

Objectives

The primary goal of the field campaigns isto validate the accuracy of the MODIS LSTalgorithm at an accuracy better than 1 Kthrough validation field campaigns. Thesecondary goal is to validate the calibra-tion accuracy of seven TIR bands at aradiance accuracy better than 0.5-1.0%through vicarious-calibration fieldcampaigns. These seven bands are used inthe day/night MODIS LST algorithm forsimultaneous retrieval of land-surfaceemissivity and temperature. Details of theMODIS LST algorithm are given in itsalgorithm theoretical basis document(ATBD) (http://eospso.gsfc.nasa.gov/atbd/modistables.html).

Ground-based TIR Instruments

In order to achieve these two objectives, acontinuous effort has been made toimprove the performance of the TIRinstruments used in ground-basedmeasurements and to establish thefollowing necessary functions:

1. accurate spectral measurements ofsurface emissivity and surface-leaving radiance in the range of 3.5 to14.5 µm,

2. spectral measurements of surface-leaving radiance at multiple viewingangles in order to compare with theMODIS observation at its exactviewing angle,

3. temporal measurements of thesurface-leaving radiance and/or LSTin order to exactly match the MODISobservation time,

4. appropriate spatial coverage andsampling of the in situ LST measure-ments for comparisons with theMODIS observation at its 1-km pixelscale,

5. accurate portable blackbodies tocalibrate TIR instruments in the field.

MODIS Land Surface TemperatureValidation-—Zhengming Wan ([email protected]), University of California, Santa Barbara, CA

proper sequence of these courses will beimportant as we have noticed a tendencyfor students to attempt GIS courseswithout the proper foundationcoursework.

A second area for future development is toexpand the availability of the introductoryEarth Systems course as a “basic” sciencecourse for all undergraduates. We con-sider that the introductory course pro-vides a sound introduction to the sciencegenerally, in addition to being the begin-ning course of the Earth Systems major.

As a full major established in both thecollege catalog and the semester schedule,Earth Systems is self-sufficient. The majorhas emerged from its formative develop-ment to take its place among the interdis-ciplinary majors offered by CSM and isavailable to other community colleges.Furthermore, Earth Systems has a brightfuture as a basis for transfer science majorsand as a basis for employment in theexpanding fields of remote sensing, GIS,and GPS.

Points of Contact:Professor Kenneth D. KennedyCollege of San Mateoemail: ([email protected]),

Professor William B. RundbergCollege of San Mateoemail: [email protected]

J. W. Skiles, Ph.D.SETI Institute, NASA Ames ResearchCenteremail: [email protected]


30

A TIR spectrometer was purchased in1993. This TIR spectrometer is equippedwith an InSb/MCT sandwich detector thatcan provide radiance data at a selectablespectral resolution of 1-to-32 wave-numbers in the spectral range of 3.5-14.5µm. The 4-wavenumber resolution wasselected in our field measurements. At thisspectral resolution, the speed of thespectrometer is 8 spectra per second. Aseries of custom improvements was madeto this TIR spectrometer, including theinstallation of a beam expander, a scan-ning mirror, three blackbody boxes infront of the spectrometer, and a watercooling system that allows the spectrom-eter to work in a more stable condition.

The field-of-view (FOV) of this improvedTIR spectrometer is approximately 25 cmwhen it is placed on a platform 3 m abovethe ground. This TIR spectrometer withthe scanning mirror can scan a range ofangles to provide temporal and angularspectral surface radiance and atmosphericdownwelling irradiance (with a diffusereflector). The measured downwellingirradiance is used in the atmosphericcorrection of the ground-based measure-ment data. The accuracy of the TIRspectrometer is better than 0.15 K in the 8-14-µm range. In this spectral range thesignal-to-noise ratio (SNR) of a singlespectrum of the TIR spectrometer isgreater than 1000. At least 256 sets ofspectra are averaged in order to obtain ahigh SNR in the medium-wavelengthrange down to 3.5 µm.

A similar TIR spectrometer was combinedwith a 5-inch infragold integrating spherefor measurements of the spectral direc-tional-hemispherical emissivity. Thisinstrument is primarily used for emissiv-ity measurements of samples such as ice,water, silt, sand, soil, and vegetationleaves.

Laboratory and field measurements of theinfrared bidirectional reflectance distribu-tion function (BRDF) and emissivity canalso be made with the UCSB SpectralInfrared Bidirectional Reflectance andEmissivity (SIBRE) instrument, whichincludes a TIR spectrometer, a hemispheri-cal pointing system, a TIR source, andreference plates. The spot size viewed bythe SIBRE instrument is approximately 3cm in diameter so materials with small-scale surface structure can be examined. Abeam expander can also be used to give a12-cm spot for larger structured surfaces.

Heimann thermometers with a FOV ofapproximately 50 cm at a distance of 2 mare used as broadband radiometers forLST measurements. Their spectral filters of10-13 µm minimize the effects of uncer-tainties in spectral emissivities on theatmospheric and emissivity corrections.

These TIR instruments are calibrated witha full-aperture blackbody in a range oftemperatures wide enough to cover thesurface-temperature conditions in thefield. A water-bathed-cone blackbody isalso used to check the accuracies of theTIR instruments (including the full-aperture blackbody) routinely in thelaboratory. High-precision thermistors(with accuracy better than 0.1 K) used inblackbodies provide the traceability to theNIST standard.

Up to 12 Heimann thermometers aredeployed at different locations over anarea ranging from 100 m by 100 m to 2 kmby 2 km in order to measure the spatialvariations at the MAS and MODIS pixelscales. Up to 16 small thermistordatalogger packages are also deployedover the lake or playa test site. Thethermistors are placed a few millimetersbeneath the lake or playa surface.

A potentially large uncertainty source in

scaling the ground-based LST measure-ments (in FOV of 25-50 cm) up to the MASand MODIS pixel size is the spatialvariation of LST at the 0.2-1-m scale. Thereare two approaches to measuring thetemporal spatial variation of LST at thisscale. One is to move a broadbandradiometer along a cable at a speed of1 m/s. Another is to measure the 2-D LSTdistribution continuously with an IRcamera. An AGEMA IR camera providesLST images in 320 lines with 240 pixels perline. In the high-speed mode, the cameracan provide 30 image frames per second.The accuracy of the averaged image ofLST each second is better than 0.3 K. Themeasured time series of the 2-D LST imageis used to analyze the temporal and spatialvariations of LST at the 0.2-1-m scale andat the MAS pixel scale (50 m).

Besides the TIR measurements, a radio-sonde is launched before the MAS and/orMODIS overpass to measure the atmo-spheric temperature and water vaporprofile. Based on the measured atmo-spheric profiles and surface emissivity andtemperature, the radiance at the top of theatmosphere (TOA) can be obtainedthrough atmospheric radiative-transfersimulations. The convolution of thederived TOA radiance with MAS/MODISspectral response functions gives theradiance values in the MAS/MODISbands corresponding to the measuredatmospheric and surface conditions. TheMAS/MODIS calibration accuracy can bedetermined from the comparison betweensuch derived TOA band radiances and theMAS/MODIS band radiances. It is highlydesirable to conduct vicarious-calibrationfield campaigns over large flat homoge-neous sites at high elevations under dryclear-sky conditions in order to effectivelyreduce the uncertainties in the measuredatmospheric conditions (due to temporaland spatial variations) and in the atmo-spheric radiative-transfer simulation.


31

Synergism of Ground-based andAirborne Measurements

Railroad Valley playa, Nevada, and thearea of Mono Lake, California, wereselected as primary test sites. The RailroadValley playa is greater than 15 km indiameter at a surface elevation of 1440 mabove sea level. The surface temperature isrelatively homogeneous in the centralportion during the dry summer season.This site is one of the test sites used tovalidate LST in the high-temperaturerange. The first field campaign with MASflights over this site was conducted jointlywith the Advanced Spaceborne ThermalEmission Reflectance Radiometer (ASTER)team and other calibration/validationscientists in August 1995. Mono Lake isgreater than 15 km in diameter at a surfaceelevation of 1945 m above sea level. Thereare forests, grasslands, and mountains inthe Mono Lake area. A flat short-grassfield of approximately 2 km by 2 km, tothe south of Mono Lake is covered bysnow for a period of several days to a fewweeks after each major snowfall. TheMono Lake area is one of the test sitesused to validate LST in the medium- andlow- temperature range.

Six field campaigns were conducted withMAS flights for the validation of MODISLST algorithms in Railroad Valley,Nevada, and in the areas of Mono Lakeand Death Valley, California, in 1995-1998.Only the data collected in the fieldcampaign conducted near Mono Lake inMarch 1998 could be used for the vicari-ous calibration of the MAS thermalchannels because of the calm clear-sky anddry atmospheric conditions during thatcampaign (column water vapor less than0.4 cm). The MAS noise-equivalenttemperature difference was estimatedwith MAS data over three lake-surfacesites (unfrozen Mono Lake, and frozenGrant Lake covered by snow and ice in its

northern and southern portions, respec-tively) and one snow-field site. The MAScalibration error was estimated with theMAS data over Mono Lake and in situ

measurement data over the snow-fieldsite. The uncertainty to be determined infuture field campaigns is involved withthe spatial variations of LST at the scalesfrom 0.2-1 m up to the MAS pixel size.Another field campaign will be conductedthere in February/March 2000 to validatethe calibration of MAS and MODIS TIRbands. Once MAS calibration is validatedand its long-term stability is establishedthrough regular vicarious calibrationactivities, MAS can be used to validate thecalibration accuracy of MODIS TIRchannels. At that point, MAS can also beused to validate MODIS LST products inareas with heterogeneous land-cover typesand/or in complicated terrains where it isalmost impossible to obtain accurateground-based measurement data at theMODIS pixel scale. The MAS dataacquired over the MODIS Land validationcore sites will also be used to validate theMODIS LST product.

Field Campaigns Planned for 1999and 2000

A field campaign over Railroad Valley, NV,and the area of Mono Lake, CA, isscheduled for the period of September 20to October 15, 1999. During this period, 16ER-2 flight hours will be used for daytimeand nighttime MAS flight missions. TheAirborne Visible Infrared ImagingSpectrometer (AVIRIS) has been requestedfor daytime flight missions. The ER-2flight schedule will be coordinated withKurt Thome of the University of Arizona,who has also requested an alternativeplatform for a MASTER (the MODIS andASTER Airborne Simulator) flight tocoincide with overpasses of ASTER andLandsat 7 during this period of time.

A vicarious calibration field campaignover the area of Mono Lake, CA, isplanned for February/March 2000. MAS/AVIRIS flights have been requested forthis campaign.

A vicarious field campaign over UyuniSalt Flats, Bolivia, is being planned forMay 2000. There will be no MAS flight forthis field campaign.

A field campaign over Railroad Valley, NV,and the area of Mono Lake, CA, isscheduled for June/July 2000 for theMODIS LST validation. MAS/AVIRISflights have been requested for thiscampaign.

Collaboration will occur during theASTER calibration/validation fieldcampaign over Mauna Loa, Hawaii, inApril-June 2000. MASTER flights havebeen requested during the PACRIM-IIdeployment.

We will join the SAFARI 2000 fieldcampaign to conduct ground-based TIRmeasurements over Makgadikgadi SaltPans, Botswana in August 2000.

Close collaboration with the ASTER teamand other groups will be maintained forfuture MODIS LST validation activities,and new opportunities for collaboration inthe international efforts to validate LST atthe global scale will be pursued.


32

Overview

The SouthernAfrican RegionalScience Initiative,SAFARI 2000,presents an opportu-nity to study global-change issues on aregional scale in acomprehensivefashion. A level ofexcitement exists atthe prospect ofcoordinating andleveraging off of existing inter-agency andinternational research activities in South-ern Africa to successfully conduct SAFARI2000. As part of the progression in thecoordination and planning of this regionalscience initiative, North American andSouthern African scientists came togetherto participate in the NASA EOS SAFARI2000 workshop held during May 12-14,1999 at the National Center for Atmo-spheric Research, in Boulder Colorado.

The Purpose of the Workshop was toreview the SAFARI 2000 science plan;identify specific measurement needs andcritical gaps in that plan; define andcoordinate aircraft platforms and activi-ties; plan and coordinate U.S. contribu-tions to the SAFARI 2000 ImplementationMeeting in Gaborone, Botswana, during

Summary of NASA EOS SAFARI 2000Workshop

— Bob Swap ([email protected]), Tim Suttles ([email protected]),Michael King, Harold Annegarn, Bob Cook, Jim Drummond, Bill Emanuel, John Gille,Peter Hobbs, Chris Justice, Luanne Otter, Stuart Piketh, Steve Platnick, Jeff Privette,Lorraine Remer, Gary Shelton, and Hank Shugart

July 26-30, 1999. Participants in theworkshop numbered approximately 60and were affiliated with various universi-ties and national government agencies.

The Boulder Workshop was conductedover 2 1/2 days. Day 1 was devoted to areview of the evolving plans for thescience initiative, the status and progressof funded and planned investigations, andkeynote presentations on each of the coreelements of the Science Plan. Thesereviews and presentations set the stage foractivities on Day 2, which includedDiscipline Breakout Groups to address thestrategy for core-element activities andpotential gaps and Airborne/SurfaceMeasurement Breakout Groups to addressthe measurement requirements andcapabilities. On the final day of the

workshop, Implementation BreakoutGroups met to define approaches forcoordinating and integrating activities ofthe science steering committee, theairborne operations teams, and theground-based measurement teams.Reports were presented on the breakoutgroup deliberations, and other discussionswere held on coordination between U.S.and in-region research activities; identifi-cation of potential collaborative partner-ships; data policy and principles; andMemorandum of Understanding, LetterAgreements, and International Protocolneeds. The final session concluded withwriting assignments to key participantswith the objective of converting theworkshop results into a U.S. Implementa-tion Plan for SAFARI 2000.

The vision of SAFARI 2000 was presentedwith the breadth of that vision havingfollowed, in part, from the remainingunanswered questions from SAFARI 92.Those questions focus on: total emissionsand magnitude of different emissionsources; varying emission estimates andthe validation of these estimates; tempo-ral, spatial, chemical, and optical charac-teristics of the regional atmosphere asrelated to these emissions; and impacts ofthese emissions on biogeochemistry,radiative forcing, air quality, and rainproduction. The concept of a SAFARI 2000Core Experiment to address many of theseunanswered questions was presented(Figure 1). The Core Experiment aims tostudy aerosol and trace-gas emissions,their transports and transformations, theirdeposition and their impacts in SouthernAfrican as determined by ground-based,and in situ and remotely sensed airbornemeasurement campaigns. The SAFARI2000 Core Experiment comprises thefollowing core elements: TerrestrialEcology; Land Cover and Land UseChange; Aerosols; Trace Gases; Cloudsand Radiation; and Modeling. Research

Clouds and Radiation

Terrestrial Ecology AerosolsSAFARI-2K Core Experiment

Regional EmissionsTransports & Transformations

Deposition

ImpactsLand Cover andLand Use Change

Biogenic

Pyrogenic

Industrial

Trace Gases

Modeling

Ecosystem Processes Biogeochemical Cycling Radiative Forcing

Transport and Deposition Emissions Modeling

Integrated Modeling

Figure 1: Schematic of SAFARI 2000 Core Experiment


33

and EOS validation activities associatedwith each of the core elements werediscussed by the discipline-specificbreakout groups.

There was some concern in the breakoutgroups, given the workshop attendeespresent at Boulder, about being able toaddress some of the objectives of theScience Plan to a sufficient level. Thebreakout groups identified the need toinvolve a broader community of scientiststo discuss ways to achieve some of theobjectives of the Science Plan. In particu-lar, the groups identified the need tostrengthen the modeling activities (e.g.,interdisciplinary modeling, integratedmodeling, transport modeling, andecological modeling). Such issues shouldbe addressed at the upcoming workshopin Gaborone.

A proposed Management Structure forU.S. participation was presented andcouched within the existing SAFARI 2000management structure. This will bedeveloped for review at the Gaboroneworkshop. Guidelines for participation inSAFARI 2000 were also presented. Theneed for interactions and negotiationsbetween U.S. and regional scientists to befacilitated by the regional and U.S.SAFARI 2000 secretariats was alsostressed. Adherence to establishedinternational protocols regarding Memo-randums of Understanding, overflightpermissions, and mutually agreeableshipping procedures were also discussed.The U.S. international agreements are tobe worked by the NASA Office of ExternalRelations and facilitated by the regionalSAFARI 2000 secretariat.

Discipline Breakout Groups

Three discipline breakout groups, LandModeling and Data, Aerosol-Clouds andRadiation, and Trace Gases, were given

the charge to evaluate the core-experimentconcept and to identify research areasdeemed important and not yet sufficientlyaddressed by SAFARI 2000. Thesebreakout groups discussed existing datasets, funded projects, and proposedprojects related to SAFARI 2000. Theworkshop participants generally reachedconsensus regarding the broad sciencegoals, the core elements and associatedactivities, and the idea of a core experi-ment associated with SAFARI 2000, but itwas concluded that questions remainconcerning informational and personnelgaps in the initiative. The workshopparticipants stressed the importance forgetting cooperation between measure-ments and modeling groups. While manyof the research activities were viewed asrelatively straightforward in terms of thedevelopment of a research strategy, othersthat were perceived as having high sciencebenefit required more discussion andinput from researchers with a differentcomplement of expertise than was presentat the workshop.

There was consensus on several crosscutting needs:1) need for an interdisciplinary model-

ing component examining interac-tions over several time and spacescales;

2) need for modest resources to supportthe integrating modeling activitiesassociated with SAFARI 2000; and

3) need to further strengthen researchcomponents that link surfaceemission processes of aerosols andtrace gases to the atmosphericchemistry and transport in the freetroposphere via the planetaryboundary layer.

Specific activities requiring additionalattention and strengthening include:

1) flux-tower measurements of tracegases (CO2, O3 and reactive nitrogenspecies) and aerosols at both theMongu and Skukuza micrometeoro-logical tower sites;

2) deposition studies, especially thosestudies focusing on the dry deposi-tion of aerosols; and

3) atmospheric profiling of the bound-ary layer and troposphere via balloonstudies, acoustic sounders, andadditional rawinsondes.

A number of proposals are currentlyunder development to address some ofthese needs. The most likely fundingsources appear to be the NASA Researchand Analysis Program and the NationalScience Foundation. The South AfricanWeather Bureau agreed to construct aproposal to submit to national, regional,and international funding agencies for theprocurement of additional rawinsondes toaugment daily ascents performed rou-tinely by regional meteorological services.

The Land Modeling and Data BreakoutGroup stressed the need for in-region fieldobservations during the initial phase ofthe growing season. Flux-tower andaerosol and trace-gas deposition data,especially for carbon, nitrogen, and sulfurfor incorporation into site-specific andregional models were stressed as program-matic needs. Involvement of the vegeta-tion canopy lidar (vcl) instrument team inSAFARI 2000 was highly desirable for thedetermination of canopy structure andfuel load. The need for climate datarecords, AVHRR-archived data, andhydrological data in terms of soil moistureand rainfall was also articulated. Theinvolvement of the Tropical RainfallMeasurement Mission (TRMM) and theirdata products in SAFARI 2000 was seen ashighly desirable. The possibility of using


34

the gauged Vaal River catchment and theSouth African Weather Bureau’s (SAWB)overlapping radar network to validate theTRMM products for the southern Africansub-continent was identified as a possibleproject that could produce a significanttest of our understanding of the hydro-logical cycle. There is a possible modelingcomparison exercise that would make useof a benchmark data set collected alongthe Kalahari Transect that could providean important regional-scale test of thecurrent site of dynamic global vegetationmodels. A clearly defined source offunding to support the necessary integra-tive and interdisciplinary modelingexercises required by SAFARI 2000 isneeded. Data issues focused on the use ofthe Oak Ridge National LaboratoryDistributed Active Archive Center (ORNLDAAC) on the U.S. side and a regionalmirror data site, most likely to be locatedin Botswana to handle and disperse thedata collected in SAFARI 2000. It isplanned that the establishment of a mirrordata center with meta-data links estab-lished by regional participants will beclarified at the Gaborone meeting.

The Aerosol-Clouds and RadiationBreakout Group discussed objectivescentered around the physical and chemicalcharacterization of aerosols and theirradiative effects, linking aerosol character-istics to fire sources, and cloud-aerosolinteraction in maritime clouds. Theimplementation strategy required toaddress those objectives was viewed asstraightforward. In terms of objectivesfocusing on the evolution of physical,chemical, and optical properties ofaerosols, biogenic aerosol, and cloud-aerosol interaction in continental clouds,the implementation strategy is not yetclear, but discussion has commenced.Similarly, linking aerosol and cloudstudies to ecological modeling, requiresfurther attention. This group also re-

quested additional ancillary data sourcesin the form of rawinsondes and drop-sondes as well as access to data sets fromthe NASA Data Assimilation Office (DAO)and the SAWB. Input from transportmodels is also required for missionplanning and post –intensive dataanalyses. A suggestion was made thatthose researchers who have the expertiseto tie aerosol transports and deposition toecological modeling provide the leader-ship necessary to address this goal ofSAFARI 2000.

The Trace Gases Breakout Group was ableto make significant advancement inmeeting the charges given to them duringthe workshop. Through their extensivediscussions and deliberations, they wereable to produce a number of recommenda-tions to the SAFARI 2000 steering commit-tee. Chief among them were the following:1) strong need for compilation and

maximum utilization of existingdatabases that include a variety offorms of printed material, CDpublications, and electronicallystored data;

2) the formation of a measurement-modeling liaison working group toaid in the designing of in situ flightplans and sampling strategies;

3) need to measure dew compositionand precipitation concentration toaddress issue of dry and wet aerosolsinks;

4) the study of frequency and intensityof lightning as a measurement ofopportunity to aid in determining theproduction of NOx;

5) need for inter-comparison of airborneand spaceborne systems;

6) enhancement of existing meteoro-logical infrastructure within theregion—augmentation of upper-airsondes and trajectory analysissupport.

7) the need to better constrain estimatesof the contributions of biogenicemissions to the budgets of aerosoland trace gases in the region.

Additional points included the need tounderstand biogenic hydrocarbonproduction, especially during the criticaltime of vegetation leaf out. The TraceGases working group also identified anumber of questions and implementationstrategies to address those questions intheir group report.

The discipline groups, especially theLand-Modeling and Data Group, ex-pressed the need for involvement ofregional scientists and their scientificinput especially in the areas of identifica-tion of surface sites and processes ofscientific interest to the SAFARI 2000effort. There was also a feeling that thoseinvestigators new to the region shouldfamiliarize themselves with the scienceand data products of existing researchefforts. Along these lines, it was suggestedthat those researchers in need of suchinformation should contact the SAFARI2000 webpage (http://safari.gecp.virginia.edu) and /or the regional coordinationsecretariat. The general feeling during theBoulder workshop was that the Gaboronemeeting is an important vehicle to furtherinteractions, discussions, and negotiationsinvolved with SAFARI 2000 collaborativeresearch activities, especially in the area ofstrengthening the land components withthe objective of being able to collaboratewith local experts and further developlogistical arrangements.


35

Aircraft Breakout Groups

SAFARI 2000 intends to use the atmo-spheric gyre as a physically integratingmechanism. This is beneficial in thatsouthern African climatologies exist thatallow for the establishment of a relation-ship between information in the long-termsatellite record and the local observationsites. Airborne measurements are essentialto achieve the goals of the experiment.Aircraft platform availability and partici-pation were discussed in detail. Theplatforms committed to involvement inSAFARI 2000 include the NASA ER-2; theUniversity of Washington Convair 580;and the South African Weather BureauAerocommander 690s. The opportunity tohave the Proteus, a newly-developed,high-altitude, high-endurance remotesensing platform received much interestfrom the workshop participants. Itsavailability to SAFARI 2000 is subject tothe Proteus team’s success in securingadditional resources.

Consensus was achieved among key U.S.and regional scientists to consolidate thescientific decision-making processesrelated to airborne operations during theAugust-September 2000 campaign atPietersburg, RSA. Coordination, commu-nications, and planning associated withaircraft missions will be conductedthrough the SAFARI 2000 aircraft mission-control center at Pietersburg. For aircraftplanning at the control center, it isessential to have daily meteorologicalforecasting and access to Meteosat SatelliteImagery. To initially facilitate this projectcoordination and planning, the August –September 2000 flying campaign willbegin with all of the aircraft involved withSAFARI 2000 based at Pietersburg for atleast one week.

The In-Situ Aircraft Group focused ondesign of the SAFARI 2000 dry-season

airborne campaigns. The experimentsrequiring in situ observations include:

Terra Underflights—radiometric calibra-tion and data product validation foraerosol retrievals, smoke/cloud masking,and fire detection and characterization;

Namibian stratus studies—cloud retriev-als and indirect effects;

Biomass burning studies—“box studies,”fire emission factors, chemical, physicaland optical evolution of emissionsdownwind of fires;

Industrial source studies—flights ofopportunity looking at possible direct andindirect forcing effects.

The types of proposed flight tracks tomeet the above needs are as follows:

1) Cross-section wall flight sampling ofthe gyre with multiple aircraft

2) Probe investigation flights of thegyre, both Lagrangian and Eulerian,by single aircraft

3) Biomass burning flights—firedetection and smoke/emissionsampling flights

4) Coordinated flights involving remotesensing observations platforms(satellite, ER-2, Proteus) and in situ

observational platforms (Convair580, Aerocommander 690A’s)

5) Marine stratus

6) Overwater flights

The various logistical needs for thesedifferent flight missions were discussed.There was general agreement concerningthe utility of convening an airborneplanning simulation exercise to be held inthe region early next year in preparation

for the August-September, 2000 intensiveflying campaign.

Recommendations

Summary Recommendations were arrivedat from the various discussions during themeeting:1) Need for the additional involvement

and funding of interdisciplinary,integrative modeling activitieslinking land and atmosphere

2) Need to strengthen links betweenground observations and airborneobservations• Augmentation of regional

rawinsonde network to profile-the free troposphere

• Acoustic sounder and pilot-balloon studies to describe theplanetary boundary layer

• Instrumentation of existingtowers for flux studies of heat,moisture, momentum, andaerosols/trace gases to describeinteractions between vegetationand boundary layer

• Aerosol and trace-gas depositionstudies to detail atmosphericcontribution to vegetatedsystems

3) Involvement of a TRMM validationactivity within SAFARI 2000 wasdeemed highly desirable

4) Coordination of all U.S.-sponsoredactivities in SAFARI 2000 through theregional secretariat office andcompliance with protocols andinternational agreements for in-country research

5) Need for funding to support regionalscientists, outside of South Africa, toparticipate in SAFARI 2000


36

The latest meeting of the EOS VolcanologyTeam was held at the University of Hawaiiat Manoa May 18th – 23rd, 1999. NumerousTeam Members were in attendance,including members from CSIRO (Austra-lia), the Open University (England), JPL,NASA Goddard, and universities inCalifornia, Michigan, and North Dakota.Many people from the University ofHawaii, including several graduatestudents, were also able to participate inthe discussions.

The main goal of the meeting was toprepare the Team for the impendinglaunch of the Terra spacecraft. A criticalpart of this preparation was a review ofthe volcano data sets that will be collectedby each instrument, since many of thehigh-resolution observations will not bemade continuously by Terra, Landsat 7, orthe foreign-partner radars. There was alsothe need to demonstrate our web-basedsoftware and the computer code that hasbeen developed by the team for theanalysis of thermal monitoring andvolcanic gas studies. Other goals were todevelop a strategy for how the Team willinteract with the media, what our publicoutreach efforts will be in the first sixmonths of the mission, and what otherdata sets are becoming available to thevolcanology community.

Report of EOS Volcanology IDS TeamMeeting— Pete Mouginis-Mark ([email protected]) Team Leader— Joy Crisp ([email protected]) Deputy Team leader

Some of the highlights of the meetingincluded:

1) Anne Kahle (JPL) reviewed the currentplans for volcano data acquisitions as anASTER Science Team Acquisition Request(STAR). Luke Flynn (Univ. Hawaii)covered the comparable acquisition plansfor Landsat 7, since he is also a Landsat 7Science Team member. Particularlyimportant will be the thermal studies ofactive lava flows and domes from ASTERand ETM+ on Landsat 7, as well as thedigital-elevation models that will bederived from stereo ASTER scenes. Morethan 30 different volcanoes around theworld will be monitored on a regular basisby the Team using these two sensors.These volcanoes include Erebus (Antarc-tica), Lascar (Chile); Galeras (Columbia);Arenal and Poas (Costa Rica); Fernandina(Galapagos Islands); Erta Ale (Ethiopia);Piton de la Fournaise (Reunion Island);Fuego, Pacaya, and Santa Maria (Guate-mala); Hekla and Katla (Iceland); Agungand Merapi (Indonesia); Stromboli,Vulcano, and Mt. Etna (Italy); Sakura-jimaand Unzen (Japan); Popocatepetl (Mexico);Ruapehu and White Island (NewZealand); Cerro Negro, Masaya, and Telica(Nicaragua); Manam and Rabaul (NewGuinea); Mayon (Philippines); SoufriereHills (Montserrat); Kilauea (Hawaii); andNyamuragira and Nyriagongo (Zaire). It is

clear that as data for these sites becomeavailable, the volcanology community atlarge will see a dramatic increase in thenumber and quality of observations thatcan be made in the thermal infrared.

2) Howard Zebker (Stanford) and HaroldGarbeil (Univ. Hawaii) have been workingextensively with radar interferometrystudies of volcanoes. The most notablerecent success has been the analysis of the1995 eruption of Fernandina volcano inthe Galapagos Islands, where the dimen-sions of an intrusive dike have beenquantified. There is a growing database ofpre- and post-eruption radar scenes thatwill provide exciting new perspectives onintrusive processes as well as the role oftopography on the emplacement of newlava flows. Additional radar studies, thistime of the 1998 eruption of Cerro Azul(also in the Galapagos Islands), areexpected to enable the flow path of thenew lava to be compared with predictionsbased on digital-elevation data collectedfrom the TOPSAR instrument.

3) Over the last year, considerable efforthas been expended by Arlin Krueger(NASA Goddard), Bill Rose and GreggBluth (Michigan Tech. Univ.), DaveSchneider (Alaska Volcano Observatory),and Fred Prata (CSIRO) on the analysis ofvolcanic plumes, and how the entrainedgas phase sometimes disassociates fromthe ash when the plume reaches highaltitude. Understanding this process isvitally important for quantitative modelsof eruption plumes as aircraft hazards,and also as impacts on short-term climatechange; for instance, the sulfate aerosolscan significantly affect the Earth’s radia-tion budget. Various Team-developedretrieval algorithms were discussed, aswell as ideas for new sensors/missions toaugment the EOS data sets. Lori Glaze(Proxemy Research) and Lionel Wilson(Lancaster Univ., England) have devel-


37

oped software for the analysis of plumegeometry with MODIS data, which hasbeen used with AVHRR data to studyplumes from the 1989 eruption of Redoubtvolcano, Alaska. This algorithm will alsobe valuable for the analysis of plumeheights, particularly if real-time MODISdata become available, due to the extremehazards posed by eruptions to aircraftencountering the plume. Arlin Kruegerreviewed the status of the retrievalalgorithms for mapping abundances ofash and sulfur dioxide using TOMS data.

4) Innovative gas studies using FTIRmeasurements were presented by PeterFrancis (Open Univ.) for Mt. Etna andMasaya. These field measurements usedhot targets placed several kilometersaway, and demonstrated the use of solarand lunar illumination sources. Thepotential for using similar ground-basedmeasurements to validate TES data forplumes was discussed. Aircraft thermal-infrared data (TIMS and AES) for sulfur-dioxide mapping at Kilauea volcano weredescribed by Vince Realmuto (JPL). Vincehas developed a new version of his sulfur-dioxide retrieval algorithm that can be runon a PC, thereby enabling many moreinvestigators to use this technique onceASTER data become available. Monitoringthe temporal variation of gas flux atvolcanoes around the world is expected tocontribute to our understanding of theglobal budgets of tropospheric andstratospheric sulfur dioxide.

5) Excellent computer demonstrationswere given by Luke Flynn and Eric Pilger(Univ. Hawaii) on the real-time detectionand analysis of volcano thermal anomaliesby GOES, the derivation of maps of sulfur-dioxide abundance in plumes (VinceRealmuto), and a new volcano databasecreated by Chris Okubo (Univ. Hawaii).The GOES data were initially used tomodel our planned MODIS thermal alerts,

but now that the full potential of theseGOES data has been realized, a number ofalternative ways of supporting this as aseparate effort are being pursued.

These web-based activities are expected tobecome even more important when Terrais flying, because they will often be theinitial method by which the volcanologycommunity will learn about the new datasets and, in the case of MODIS thermalalerts, as near-real-time observations. TheMODIS alerts will be presented via asimilar web-based interface and will coverthe Earth once every 1.5 days. Global,regional, and special-interest volcanomaps will provide easy access to near-real-time MODIS data of hot spots. In additionto building a comprehensive database forfuture science investigations of volcanothermal activity, they will also help theTeam to direct high-resolution instrumentssuch as ASTER, and Landsat 7, and EO-1instruments to designated targets.

6) A series of brief discussions of the radarremote-sensing and topographic studiesbeing conducted by investigators fromHawaii was provided. These presentationsincluded a new method for the determina-tion of lava effusion rates from time-seriesanalysis of digital-elevation models (ScottRowland, Univ. Hawaii), temporal studiesof lahar formation at Mt. Pinatubo (RonnieTorres and Steve Self, Univ. Hawaii), andthe analysis of catastrophic landslideemplacement on Socompa volcano, Chile(Mary MacKay, Univ. Hawaii). All of thesestudies hold great promise for the Team’sability to work with new digital-elevationdata to be produced from ASTER and theup-coming SRTM, VCL, and ICESatmissions. Topographic difference maps,that can estimate volumetric rates ofchange, were seen to hold particularpromise for studying active volcanoes.

Outreach efforts were also discussed. A

lively debate ensued during this part ofthe meeting, as many of the volcaniceruptions seen by Terra and other space-craft will have immediate social andeconomic impacts. Where real-time databecome available (for example, via MODISDirect Broadcast), great care will have tobe taken to follow the appropriate agencyprocedures when contacting the respon-sible officials (e.g., IAVCEI, 1999). Thiscare must be included whenever pressreleases are written by the Team and theEOS Project Science Office, as well as ourother interactions with the media (alwayscontacting responsible officials before thepress). The IDS Team has already estab-lished strong ties with foreign volcanoobservatories through the real-timecollection and analysis of GOES thermaldata. These data are displayed on a publicWeb site in the form of maps of locationsof thermal alerts in near real-time, whichcan be viewed and interpreted by anyone.In no case are remote-sensing interpreta-tions by the EOS Volcanology Teamreleased directly to the general public;rather there is always a local responsiblevolcanologist who is informed of theobservations and then takes the appropri-ate steps. It was recommended that thesame attention to detail concerning thepotential impact of the Terra data on localand foreign communities dealing withvolcanic activity be followed. Warnings orforecasts should not be made based onremote-sensing data alone. It should beleft up to the on-site volcanologist teamleader or spokesperson to incorporate theremote-sensing information into theirdecisions and statements.

We also heard about preliminary plans topresent a workshop at the upcomingInternational Association of Volcanologyand Chemistry of the Earth’s Interior(AVCEI) meeting next year. In addition,members of the Team are in the finalphases of editing a Monograph for the


38

What are kids doing after school? Ifthey’re like the more than 250,000 kidsworldwide who annually participate inthe Odyssey of the Mind (OM), they areputting after school hours to good usetowards a positive end—a trip to theannual Odyssey of the Mind World Finals.The University of Tennessee-Knoxvillehosted more than 5500 finalists, fromkindergarten through college age, May 26-29, 1999 at the largest creative problem-solving competition for children andyoung adults.

Odyssey of the Mind long-term problemsare creative challenges that encourage kidsto think divergently; in other words, tostretch their imaginations and developskills that will serve them well in the realworld, where there is not always one rightanswer for every question. This year,NASA’s Earth Science Enterprise, througha grant, proudly sponsored one of the five

long-term problems, the “EnvirOMentalChallenge.”

By sponsoring an OM problem, it wasNASA’s goal to inspire students to gain abetter understanding of the globalenvironment by exploring the interactionbetween the Earth’s systems of air, land,water, and life. OMers participating in theEnvirOMental Challenge problem thisyear were given the task of finding anenvironment that an Earth species can livein. One of OM’s overall goals is to helpstudents learn real-world skills such as“working with others as a team, evaluat-ing ideas, making decisions, and creatingsolutions.”

“Having NASA as a sponsor really gaveus a jumping off point. They definitelyinfluenced the nature of the problembecause they are one of the only organiza-tions that studies the entire Earth.” said

NASA’s Earth Science EnterpriseParticipates in the Odyssey of the MindWorld Finals— Steve Graham ([email protected]), EOS Project Science Office,

Raytheon ITSS

American Geophysical Union on the“Remote Sensing of Active Volcanoes”that we hope will introduce manytraditional geologists to satellite remote-sensing methods. Ideas for a secondreview article in an international journalfor the Team’s approach to volcano remotesensing were also discussed.

Finally, the meeting ended with aninformative trip to Kilauea volcano on theBig Island. The focus of this trip was toexplore some of the ASTER calibration/validation sites that may be used duringthe Terra mission, as well as to identifysome possible study sites for joint Univ.Hawaii/CSIRO aerosol studies. We alsovisited some active lava flows and oceanentry points. It rained much of the time!

More details of the Volcanology Team’sefforts are available at: http://www.geo.mtu.edu/eos/

The real-time use of GOES data forvolcano monitoring can be seen at:http://volcano1.pgd.hawaii.edu/

Reference

IAVCEI Subcommittee for Crisis Protocols,1999: Professional conduct of scientistsduring volcanic crises. Bulletin Volcanol.,60: 323-334.


39

Lynn Macey, Co-International ProblemCaptain.

Teams of 5 to 7 students compete in one offour age groups, with divisions beingdetermined by the age of the oldest teammember. All teams receive the sameproblems. However, the complexity oftheir solutions varies according to theirage group and all are judged on creativity,design, and style.

Teams choosing to solve theEnvirOMental Challenge presented aperformance about an Earth species thatrequired atmosphere, water, and land forsurvival, and whose home habitat suffereddisruption and was deemed uninhabit-able. Four potential new habitats wereavailable but whether the Earth speciescould live in any of them was unknown.During the performance, the teamcollected samples representing atmo-sphere, water, and land from the habitatsand analyzed them with a discriminatingdevice to determine whether each habitatwas suitable for the species. The result ofthe evaluations had to be communicatedby a non-verbal method and displayed ateach habitat. The teams’ performanceswere limited to 8 minutes for theirperformance, and they could spend nomore than $100 on materials.

The EnvirOMental Challenge wasdesigned to encourage students to thinkcritically and cooperatively about acomplex problem in the same way thatEarth scientists, weather forecasters,farmers, fishermen, politicians, andplanners must confront the dual challengeof understanding how natural processesaffect humanity, and how we affect thosesame natural processes. NASA is proud toinclude OM in a long list of partners whoare working together to improve ourknowledge of the Earth and to use thatknowledge for the benefit of all humanity.

In addition to sponsoring theEnvirOMental Challenge, members ofGSFC’s EOS Project Science Office hostedan Earth Science Enterprise exhibit at the1999 World Finals. Posters, Lithographs,Fact Sheets and other outreach andeducational materials were distributed toapproximately 8000 students, coaches, andparents during the four-day finalstournament. During the exhibition, manyof the students, coaches, and parentsexpressed sincere thanks for NASA’ssupport and also commented that theEnvirOMental Challenge was the mostchallenging and rewarding of this year’sfive problems.

Now in its 20th year, Odyssey of the Mindinvolves children and adult volunteers in

50 states and 42 countries. Each Septem-ber, kids anxiously await the unveiling ofthe year’s challenges, and then form teamsto develop a unique solution. Workingwith an adult coach who can steer but notadvise them, teams typically develop, test,abandon, and redevelop a variety ofsolutions before perfecting the one they’lltake to local competition. If they prevail atlocal tournaments, they’ll move on toregionals and then World Finals. The OMAssociation, Inc., provides curriculum andsupport materials for teachers who wantto incorporate the competition’s spirit ofcreative problem solving into dailyclassroom activities.

See table below for the results of the 1999World Finals EnvirOMental Challenge.

Division I1. Del Prado Elementary School Boca Raton, FL2. Valwood School Valdosta, GA3. North School Des Plaines, IL4. Glenlyon-Norfolk School Victoria, BC5. Trombly Elementary School Grosse Pointe Par, MI6. Wright City Elementary School Team B Wright City, MO

Division II1. Londonderry Middle School Team Orange Londonderry, NH2. Walker Middle School Salem, OR3. Powell Middle School Littleton, CO4. Blalack Middle School Carrollton, TX5. Lindbergh Middle School Team A Peoria, IL6. Waterford O E O/Gold Program Waterford, MI

Division III1. Georgetown Ridge Farm High School Team B Georgetown, IL2. Greenville High School Greenville, TX3. Fergus Falls Middle School Fergus Falls, MN4. Monson Jr/Sr High School Team A Monson, MA Ft. Meyers High School Team A Fort Myers, FL5. Lavista Jr High School Team B Lavista, NE Heritage High School Littleton, CO6. Pinkerton Academy Team A Derry, NH

Division IV1. University of Texas/Dallas Richardson, TX2. Sierra Nevada College Incline Village, NV


40

“NASA Satellites May ’Revolutionize’Earth Sciences,” The Chronicle of Higher

Education (July 9) by Kim A. McDonald.Over the next four years NASA’s EarthObserving System will launch 26 satellitesto measure Earth’s climatic system ingreater detail and more comprehensivelythan ever before. Durng the workshop,Future Directions in Global Change Research:

A Workshop for Journalists, that was held onJune 24, James Hansen (NASA GISS),Ghassem Asrar (NASA HQ), Michael King(NASA GSFC), Yoram Kaufman (NASAGSFC), Mark Abbott (Oregon State Univ.),Steven C. Wofsy (Harvard Univ.), andDavid Randall (Colorado State Univ.)discussed the scientific plans and satellitemissions that will examine the Earth’sclimate.

“Lack of Icebergs Another Sign of GlobalWarming,” Science (July 2) by BerniceWuethrich. For the first time in 85 years,the International Ice Patrol did not issue asingle bulletin about icebergs. John M.Wallace (Univ. of Wash.) says that sincethe 1980s, winter temperatures have risenat least 0.5 degreess Celsius.

“Jet Contrails Likely to Add to Earth’sWarming,” Reuters (June 23). Jet contrailswill contribute significantly to globalwarming within the next 50 years. PatrickMinnis (NASA LaRC) has been studying

contrails over parts of the United Statesand Europe. Minnis’ team calculated thatby 2050 the average contrail cover over theUnited States will increase 2.6 timescurrent levels.

“Craft to Track Climate-Affecting Link ofSea and Wind,” New York Times (June 15)by Warren E. Leary. The continuousinterplay between wind and oceaneventually affects Earth through itsinfluence on weather and climate.Ghassem Asrar (NASA HQ) says thatQuikScat will study this crucial interactionthat up till now has gone unmonitored.

“Enormous Haze Found Over IndianOcean,” New York Times (June 10) byWilliam K. Stevens. Scientists havediscovered that a haze of air pollutionabout the size of the United States coversthe Indian Ocean in the winter.Veerabhadran Ramanathan (Scripps) saysthat it is too early to say whether this hazehas a cooling or warming effect onclimate.

“Scientists Predict NYC Storm Surges,”Associated Press (June 4) by Jeff Donn. NewYork City could suffer huge storm surgesas often as every several years if the searises as expected during the comingcentury. Cynthia Rosenzweig (NASAGISS) says that the surges could break

— Emilie Lorditch ([email protected]), EOS Project Science Office, GoddardSpace Flight Center, Greenbelt, MD 20771

Special awards were also given to thoseteams displaying exceptional creativity.This year’s Ranatra Fusca Award was givento a Division II team for their develop-ment of an extremely unusual method ofsample discrimination for theEnvirOMental Challenge. Congratulationsto the team from Central Middle School inWhite Bear Lake, Minnesota. Their uniqueand “out of the box” solution involved the“parrot” team members physicallybecoming an integral part of the fourhabitats. They made an intuitive leap todiscriminate elements qualities using anassembly-line process, making each parrotan element specialist.

The Outstanding OMer Award recognizesthose OMers coaches, individuals, teammembers, parents, officials, and othersthat serve as OM examples or role modelsby their actions or words. It is alsobestowed on team members who exhibitexceptional skill, as opposed to creativity.As with the Ranatra Fusca Award givenfor creativity, recipients of the Outstand-ing OMer award receive a special medal.Two of this year’s recipients were partici-pants in the EnvirOMental Challenge.Congratulations to Bruna Andrade ofColegio Int. DeCarabol in Valencia,Venezuela. After the contamination of allher team members Bruna realized shecould not get to the remaining 2 habitatsin any safe manner and employed humorto include the audience in her thoughtprocesses. She ad-libbed, while maintain-ing her poise, stayed in her character, andproceeded with the role playing of aFortune Teller trying to read the suitabilityof the 2 remaining habitats through theuse of her crystal ball. Congratulations toMeg Waddell of Hightower Trail MiddleSchool in Marietta, Georgia. Meg com-posed an original “Oreawhale” song in theItalian Bel canto style. She also invented

EOS Scientists in the NewsEOS Scientists in the News

EOS Scientists in the NewsEOS Scientists in the News



41

through barrier islands and flood low-lying parts of lower Manhattan, Brooklyn,Queens, and other places in the metropoli-tan area.

“Twin Cyclone Pattern Linked to Floodingof Yangtze River,” Associated Press (June 3)by Jeff Donn. Scientists have found a linkbetween weather patterns that canpotentially be used to help predictdevastating floods in China’s YantgzeRiver. William Lau (NASA GSFC) ob-served a pair of early May cyclones overthe Indian Ocean that seemed to delay, bya week, the onset later that month of thestorm pattern known as the South ChinaSea monsoon.

“Snowpack Here Could Shrink in FutureYears,” Associated Press (June 2). ThePacific Northwest could be facing moreraining and flooding, but also a shortageof usable water in the coming decades.Dennis Lettenmaier (Univ. of Washington)says that the region’s mountain snow-packs could decline drastically within thenext 25 years because of global warming.

“NASA Says Polar Winds Might CauseWinter Storms,” Reuters (June 2). Risingwinter temperatures across the NorthernHemisphere are expected to generate morewinter storms. In a study published inNature, Drew Shindell (NASA GISS)reports that warmer winters bring wetweather to Europe and western NorthAmerica with western Europe being theworst hit by storms off the Atlantic Ocean.

“Politics Keep Earth-Viewing SatelliteEarthbound,” New York Times (June 1) byWarren E. Leary. Triana, the Earth-viewingsatellite initiated by Vice President AlGore, has been criticized because of itsorigin and mission. However, StevenWofsy (Harvard Univ.) says that althoughhe was initially skeptical about Triana, heis impressed at how carefully planned the

experiments are. Triana’s main objective isto continuously monitor the Earth’s entiresunlit face.

“Finding Ocean Temps in the Ice,”Christian Science Monitor (May 21) by PeterN. Spotts. Drew Shindell (NASA GISS)says that climate models suggest thatglobal warming could strengthen theArctic Oscillation near the North Pole andlead to changes in snowfall and rainfallpatterns in Eurasia, a shift in NorthAtlantic fishing grounds, and even thedisappearance of Arctic ice in the summer.

“New Focus of Climate Fears: Altered AirCurrents,” New York Times (May 18) byWilliam K. Stevens. A new study suggeststhat events like El Niño will occur morefrequently because of the impact of globalwarming on current air patterns. KevinTrenberth (NCAR) says that the frequencyof El Niño events is dependent on howlong tropical storms take to recharge theirheat source.

“Ozone Optimism,” Christian Science

Monitor (May 3) by Peter Spotts. Globalagreements to slow the production ofozone-destroying chemicals are working,says Michael Prather (Univ. of Californiaat Irvine) in a study published in Nature.But more needs to be done to reduceemissions of compounds like CFC-12 thatattack ozone.

“NASA Gives Kids Window on NorthPole,” CNN Interactive (April 27). A newNASA World Wide Web site gives peoplepossibly their only chance to see the NorthPole. Scientists from NASA’s GoddardSpace Flight Center are testing ozonelevels, measuring ice thickness, testingwater and soil pH, as well as participatingin online chat sessions. Students can e-mail the scientists and also watch themlive as they conduct their research.

“La Niña is on Its Way Out,” CNN

Interactive (April 26). La Niña is beginningto fade, reveals an image from the U.S.-French TOPEX/Poseidon satellite. Theimage shows that conditions in theequatorial Pacific Ocean are slowlyreturning to normal, but it also suggeststhat current ocean temperatures are stillabnormal.

“Disappearing Ice Down South,” Science

News (April 24) by Richard Monastersky.The glacial shelves surrounding theAntarctic Peninsula are melting because ofincreased temperatures in the region. TedScambos (Univ. of Colorado) says thismelting has no impact on global sea-levelrise, because the ice shelves are alreadyfloating in water.

“El Niño May Slow Global Warming,”CNN Interactive (April 15). The oceanreleased 30-80 percent less carbon dioxideduring the El Niño years of 1991-1994,reports a study published in Nature.According to Scott Doney (NCAR), thestudy, which used data from 80 weatherstations, captured an important timeperiod in showing what is happening tocarbon dioxide during an El Niño event.

“NASA Launches New Earth-ImagingSatellite,” Associated Press (April 15).NASA’s Landsat 7 satellite will monitorglobal conditions ranging from landsurface change and snow packs to floodsand fires, reports Darrel Williams (NASAGSFC). Williams says that Landsat 7 wasdesigned to monitor the same area every16 days.

“Two Scientists Find a Mission at Hamp-ton U.,” The Chronicle of Higher Education

(April 9) by Jason Hughes. James M.Russell III (Hampton Univ.) and M.Patrick McCormick (Hampton Univ.)formerly of NASA’s Langley ResearchCenter, took positions at Hampton


42

Your One-Stop for NASA Education

NASA’s Earth Science Education Programis working to better leverage Enterpriseendeavors through the NASA EducationHome Page. The goal is to make theNASA Education Homepage a one-stop“shopping” site for educators whereeverything related to NASA education isposted and linked from this site. You canvisit the site at: http://education.nasa.gov.

First NASA Earth Science EducationForum will be held in Austin

The NASA Earth Science Education Forumwill be held November 14-17, 1999 inAustin, Texas, at the Omni DowntownHotel. This will be the first time thatNASA brings together members from allparts of its Earth science educationprogram, from elementary throughuniversity level projects, including Earthscience and education representativesfrom NASA Headquarters, all NASA FieldCenters, universities, non-profit organiza-tions, and private companies.

The conference is intended to meet thefollowing objectives:• Communicate NASA’s Earth science

education strategy and vision for thefuture.

• Share knowledge and experiencegained as a result of NASA ESEeducation activities.

Earth Science Education ProgramUpdate— Nahid Khazenie ([email protected]), Education Program Manager, Office of

Earth Science, NASA Headquarters

• Encourage leveraging and coopera-tion among projects.

• Share resources and unique ap-proaches to enhance current pro-grams.

As a result of the conference, NASAhopes to:• Identify possible gaps in its overall

Earth science education program.

• Identify the extent of equity, diver-sity, and access in all activities.

* Identify overall program improve-ments.

The Institute for Global EnvironmentalStrategies (IGES) is organizing this eventand has developed a conference WWWsite, where you can register on-line athttp://www.strategies.org/conference.html. For more informationabout the conference or to register, pleasevisit the WWW site or contact TheresaSchwerin, email: [email protected].

Terra Launch Conference forEducators

A conference for educators will beconducted in conjunction with the AtlasCentaur launch of the Terra Earth Sciencesatellite at Vandenberg Air Force Base,California.

University to increase interest in physicsamong black students. The program isgaining momentum in its second semesterwith 12 undergraduate and three graduatestudents.

EOS researchers please send notices ofrecent media coverage in which you havebeen involved to: Emilie Lorditch, EOSProject Science Office, Code 900Goddard Space Flight Center, Greenbelt,MD 20771. Tel. (301) 441-4031; fax: (301)441-2432; e-mail: [email protected]

an “orea” language using no EnglishWords. The hauntingly beautiful melodyconveyed perfectly the emotion of theheart-broken whale. She applied heroutstanding musical talent in an unusualand effective manner.

OM estimates that approximately2,140,000 students, parents, teachers,administrators, and spectators wereexposed to the EnvirOMental Challengeover the course of the 1998/99 school year.Talk about a return on your investment!

(Continued from page 40)

NASA’s Earth Science EnterpriseParticipates in the Odyssey of theMind World Finals


43

Terra ushers in a series of Earth-orbitingsatellites that will enable researchers tounderstand how the atmosphere, land,and ocean interact with each other on aglobal scale. Instruments provided by theUnited States, Canada, and Japan willsimultaneously study clouds, water vapor,aerosol particles, trace gases and terrestrialand oceanic properties. In addition theywill measure the changes in land andocean surface and interaction with theatmosphere through exchanges of energy,carbon, and water. Curriculum areas mostaffected by Earth Science research include:water, coastal, agriculture, forestry andrange resources; geology, environmentalmonitoring, and land use. Terra Projectscientists, engineers, and the educationalcommunity will address the science,technology, and classroom applicationsassociated with the mission.

NASA and the California Central CoastNASA Educator Resource Center, incooperation with the U.S. Air Force, willhost the conference. For further informa-tion, please call (650) 604-5543 or go to theTerra web site at http://terra.nasa.gov.

El Niño Pudding

‘El Niño pudding’, a great activity anddelicious treat, and its link to the globalclimate event are now staged on thehighly acclaimed NASA children’s site;SpacePlace at http://spaceplace.jpl.nasa.gov/topex_make1.htm.

September 20-24Conference on Sensors, Systems and NextGeneration Satellites V, University of Florence,Italy. Call for Papers. Contact Steve Neeck,email: [email protected].

November 2-5The CEOS Global Observation of Forest Cover(GOFC) Meeting on Fire Mapping andMonitoring, the Joint Research Center, Ispra,Italy. For further information contact FrankAhern, email: [email protected]

2000

March 27-3128th International Symposium on RemoteSensing of Environment, Cape Town, SouthAfrica. Call for Papers. For abstractssubmission: [email protected] orhttp:www.isrse.co.za, Fax: +27 21 883 8177;Tel: +27 21 886 4496 (ask for Deidré Cloete);postal: The 28th ISRSE technical committee,PO Box 452, Stellenbosch, 7599, South Africa.

May 22-26ASPRS: The Imaging and GeospatialInformation Society, 2000 Annual Conference,May 22-26, 2000. Washington DC. Call forPapers. For abstracts submission see URL:http://www.asprs.rog/dc2000; tel. (410) 208-2855; fax: (410) 641-8341; email:[email protected]

July 24-28IEEE 2000 International Geoscience andRemote Sensing Symposium, 20thAnniversary, Hilton Hawaiian Village, Honolulu,Hawaii. Call for Papers. For up-to-date dataregarding submissions, access the conferencewebsite at www.igarss.org.

EOS Science Calendar

September 22TES Science Team meeting, HarvardUniversity, Cambridge, MA. For localarrangements Contact: Daniel Jacob, tel. (617)495-1794, email: [email protected]; foragenda information contact Reinhard Beer, tel.(818)354-4748; email: [email protected].

September 28-30NSIDC DAAC User Working Group Meeting(PoDAG) Boulder, Colorado

Global Change Calendar

August 2-618th Congress of the InternationalCommission for Optics, San Francisco, CA.Contact: ICO XVIII Conference Manager, SPIE,1000-20th Street, P.O. Box 10, Bellingham, WA98225, tel. (1) 360 676 3290; Fax: (1) 360647 1445; email: [email protected]

September 8-10Non-CO2 Greenhouse Gases (NCGG-12)Scientific understanding, control andimplementation, Noordwijkerhout, TheNetherlands. Call for Papers. Contact Joop vanHam, e-mail [email protected], Fax: +31-15-261 3186.

September 13-15IEEE International Workshop on MultimediaSignal Processing, Copenhagen. Contact Jenq-Neng Hwang, e-mail: [email protected], URL: http://eivind.imm.dtu.dk/mmsp99/

September 13-17Sixth Scientific Conference of the InternationalGlobal Atmospheric Chemistry Project (IGAC),Bologna, Italy. Call for Papers. URL: http://www.fisbat.bo.cnr.it/IGAC99/.

September 15-17Second International Workshop on Multi-angular Measurements and Models, ISPRA,Italy. Contact Michel Verstraete, e-mail:[email protected], URL: http://www.enamors.org.

Code 900National Aeronautics andSpace Administration

Goddard Space Flight CenterGreenbelt, Maryland 20771

Official BusinessPenalty For Private Use, $300.00

Printed on Recycled Paper

Bulk Rate MailPostage and Fees PaidNational Aeronautics andSpace AdministrationPermit G27

The Earth Observer

The Earth Observer is published by the EOS Project Science Office, Code 900, NASA Goddard Space Flight Center,Greenbelt, Maryland 20771, telephone (301) 614-5559, FAX (301) 614-6530, and is available on the World Wide Web athttp://eos.nasa.gov/ or by writing to the above address. Articles, contributions to the meeting calendar, and sugges-tions are welcomed. Contributions to the Global Change meeting calendar should contain location, person to contact,telephone number, and e-mail address. To subscribe to The Earth Observer, or to change your mailing address, pleasecall Jim Closs at (301) 614-5561, send message to [email protected], or write to the address above.

The Earth Observer Staff:

Executive Editor: Charlotte Griner ([email protected])Jim Closs ([email protected])

Technical Editors: Bill Bandeen ([email protected])Renny Greenstone ([email protected])

Design and Production: Winnie Humberson ([email protected])Distribution: Hannelore Parrish ([email protected])