MODIS Ice Cloud Retrieval Statisticsin the TC4 Region

July 2007

MODIS analysis for TC4 region– 5°N - 15°N, 90°W - 75°W

1D probability density functions– Optical thickness and effective radius

(land vs ocean; Terra vs Aqua) Regional images

– Cloud mask (Terra)– Optical thickness and effective radius

(land vs ocean; Terra vs Aqua) 2D probability density functions

– Optical thickness vs effective radius (land vs ocean; Terra vs Aqua)

Michael D. King, Steven Platnick, and Paul A. HubanksNASA Goddard Space Flight Center

MODIS Terra & Aqua Cloud Optical ThicknessIce Clouds (July 2007)

LandLand OceanOcean

Blue = TerraRed=Aqua

MODIS Terra & Aqua Cloud Effective RadiusIce Clouds (July 2007)

LandLand OceanOcean

Blue = TerraRed=Aqua

MODIS TerraCloud Fraction Regional Maps (July 2007)

MODIS Terra & Aqua Ice Cloud Regional Maps (July 2007)

MODIS Terra & Aqua Ice Cloud re Regional Maps (July 2007)

MODIS Terra Ice Cloud and re Joint Histograms(July 2007)

MODIS Terra Water Cloud and re Joint Histograms(July 2007)

Summary of MAS/MASTER/MODIS Activities

Optical/microphysical retrieval issuesOptical/microphysical retrieval issues– Thin cirrus limitations: sun glint, surface reflectanceThin cirrus limitations: sun glint, surface reflectance

Some false detection of water clouds in ice cloud regimesSome false detection of water clouds in ice cloud regimes Cloud mask identifies thin stratus in sunglint region as probably clear in MODIS Cloud mask identifies thin stratus in sunglint region as probably clear in MODIS

production; turned off for these comparisonsproduction; turned off for these comparisons

– Comparison with other instruments/techniques, including:Comparison with other instruments/techniques, including: Remote sensingRemote sensing

IR techniques (MASTER/SHIS with MODIS)IR techniques (MASTER/SHIS with MODIS)

Radar/lidar (CRS, EDOP, CPL with MODIS) for cloud top altitudeRadar/lidar (CRS, EDOP, CPL with MODIS) for cloud top altitude

Water path/particle size (SSFR with MASTER/MAS and MODIS)Water path/particle size (SSFR with MASTER/MAS and MODIS) In situ: CIN, size distributions, etc.In situ: CIN, size distributions, etc.

Science - why do these retrievals matter?Science - why do these retrievals matter?– Establish accuracy of remote sensing of cloud microphysicsEstablish accuracy of remote sensing of cloud microphysics

Important for assessing any indirect effects of aerosols on cloudsImportant for assessing any indirect effects of aerosols on clouds

– Establish accuracy of cloud top altitude algorithmEstablish accuracy of cloud top altitude algorithm Compare MAS/MASTER & MODIS retrievals with CALIOP, CPL, and OMICompare MAS/MASTER & MODIS retrievals with CALIOP, CPL, and OMI

– Establish confidence in thin cirrus and multilayer cloud detectionEstablish confidence in thin cirrus and multilayer cloud detection Intercomparisons with MAS/MASTER and CPL on ER-2Intercomparisons with MAS/MASTER and CPL on ER-2 Intercomparisons with POLDER on PARASOL and CALIOP on CALIPSOIntercomparisons with POLDER on PARASOL and CALIOP on CALIPSO

MODIS Cloud Optical ThicknessMODIS Cloud Optical ThicknessLiquid Water CloudsLiquid Water Clouds

LandLand OceanOcean

True Color Composite (0.65, 0.56, 0.47)True Color Composite (0.65, 0.56, 0.47)

True Color and Cloud Top PressureTrue Color and Cloud Top PressureTerra/MODISTerra/MODIS

Cloud Top Pressure (hPa)Cloud Top Pressure (hPa)

Cloud Top Pressure (hPa)Cloud Top Pressure (hPa)

July 29, 2007July 29, 2007

10001000100100 550550 850850250250 400400 700700

IceIce100100 10010011 11 10101010 3030

IceIce606066 22 161647472020 99 2323

Liquid WaterLiquid WaterLiquid WaterLiquid Water3333

Cloud Optical Thickness and Effective RadiusCloud Optical Thickness and Effective RadiusTerra/MODISTerra/MODIS

July 29, 2007July 29, 2007

Cloud Optical ThicknessCloud Optical Thickness Cloud Effective Radius (µm)Cloud Effective Radius (µm)