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ARM Water Vapor Measurements for Validation and Analysis Jim Mather Technical Director for the ARM Climate Research Facility. The ARM Climate Research Facility. ARM is a United States Department of Energy climate research user facility. Objectives of the ARM facility: - PowerPoint PPT Presentation
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ARM Water Vapor Measurements for Validation and Analysis
Jim MatherTechnical Director for the ARM Climate Research Facility
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The ARM Climate Research Facility
ARM is a United States Department of Energy climate research user facility.
Objectives of the ARM facility: Provide the national and
international scientific community with the infrastructure needed for scientific research on global change
Global change research includes the study of alterations to climate, land productivity, oceans, water cycle, atmospheric chemistry, and ecological systems
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Overview: Facility Components
Research sites – permanent, mobile, and aerial Instruments and measurements Data processing, data quality, Data Archive Field campaigns – ground-based and airborne
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Overview: Research Sites
Southern Great Plains, SGP (1993) North Slope of Alaska, NSA: Barrow (1998) and Atqasuk (1999) Tropical Western Pacific, TWP: Manus (1996), Nauru (1998), and Darwin (2002) First ARM Mobile Facility, AMF (2005); Second ARM Mobile Facility (2010) ARM Aerial Facility, AAF (2007)
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Cloud profiles: millimeter radar and lidar Temperature/relative humidity/wind
profiles: radiosondes (Vaisala RS-92) Column water: microwave radiometer Column aerosol: solar spectral
radiometer In situ aerosol optical and cloud
nucleation properties Surface radiation budget: solar and
terrestrial IR radiometers Surface meteorology: T/RH/wind
Additional instruments being deployed through the Recovery Act
Overview: Measurements and Instruments
Water Vapor Instrumentation
At All Sites
Vaisala RS-92 Radiosondes launched 2-4 times/day Radiometrics 2-channel (23 GHz, 31 GHz) Microwave Radiometers
(in the process of replacing these instruments with updated versions that include a third 90 GHz channel) – gives column integrated vapor
Atmospheric Emitted Radiance Interferometers (AERIs) or equivalent (spectral zenith radiance with 1 cm^-1 resolution) - can be used to derive water vapor profiles
Multi-filter Rotating Shadowband Radiometer including a 940 nm channel water vapor channel (there is an array of MFRSRs around the SGP) – can be used to derive column integrated water vapor
Surface humidity (including tower profiles at the SGP and NSA)
Water Vapor Instrumentation, Cont.
The full array of water vapor instruments were available at the Southern Great Plains beginning in 1996 and operate to the present.
Each site was subsequently deployed with this suite with the exception that an AERI has never been deployed on Manus (though that will change this year with the Recovery Act.
Recovery Act: Introduction $60M from DOE Office of Science for investments in
instrumentation and research infrastructure 3-dimensional measurements of cloud scale dynamics,
microphysics, and precipitation Enhanced measurements of:
atmospheric aerosol absorption, scattering, composition and chemistry
cloud composition Use new knowledge to improve the predictive
performance of climate change models Over 120 individual procurement actions and
50 datastreams
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Lidars
SGPNSATWP-DTWP-MAMF2AMF1
HSRLRamanDopplerMPLMPL UpgradesCeilometer
Research Sites
Mentoring/Science/Engineering: Rob Newsom and John Goldsmith
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Raman Lidar - Darwin
First light data (water vapor mixing ratio) from the newly installed Raman lidar at the Darwin ARM site. (Plot courtesy Dave Turner).
In addition to the new Raman lidar in Darwin, there has been a Raman lidar at the SGP since 1998 (Ferrare et al., 2006, JGR).
Radiometry
SGPNSATWP-DTWP-MAMF2AMF1
Sun PhotometerAERIAERI-Extended RangeMWR-Three ChannelSolar Array Spectrometer
Research Sites
Mentoring/Science/Engineering: Laurie Gregory, Joe Taylor, Maria Cadeddu, and Connor Flynn
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RadiometerySpectral radiation data can provide information about water vapor and other gases The Solar Array Spectrometer: Measures zenith radiance and
hemispheric irradiance over the range 0.35 – 1.7 mm (2.5 nm res. below 1 mm and 5 nm above 1 mm)
AERI: Measures zenith radiance over the range 3-19 mm (1 cm-1 res.)
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A retrieval is being applied to SGP AERI data to derive temperature and water vapor profiles. (Feltz et al., 2003. J. Appl. Met.)
Radars
SGPNSATWP-DTWP-MAMF2AMF1
X-Band Precipitation C-Band PrecipitationKa-X Band CloudKa-W Band CloudMMCR Upgrades
Research Sites
Mentoring/Engineering: Kevin Widener and Nitin Bharadwaj
Value-Added Products: Scott Collis and Karen Johnson
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Radar RetrievalsARM is deploying a variety of scanning radars including X-band radars at the SGP and NSA sites and C-band radars at the SGP and TWP/Manus sites. While these radars are intended primarily to measure spatial distribution of clouds and precipitation, it has been shown recently that scanning radar data can be used to derive near surface spatial distributions of water vapor.
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Comparison of low-level water vapor derived from the NCAR S-Pol radar at a point with in situ measurements, overlaying profiles from a Raman lidar (Weckwerth et al., 2005, J. Appl. Met.).
While shown here for a point, such a technique can be used to derive spatial variability of low-level water vapor.
Field CampaignsIn addition to its continuously operating sites, ARM supports field campaign operations for shorter periods, generally (though not always) in support of the operational sites. Field campaigns can include:
Airborne measurements Enhanced radiosonde operations (e.g. increased frequency or spatial
networks) Guest instruments
See a list of past campaigns
http://www.arm.gov/campaigns/table
For More InformationContact Jim Mather at [email protected]
or visit the ARM web site: http://www.arm.gov/
particularly the measurements page dealing with atmospheric moisture:http://www.arm.gov/measurements/atmmoist
To learn how to propose a field campaign or browse past campaigns:http://www.arm.gov/campaigns
To order data: http://www.archive.arm.gov/