CloudSat Update Deborah Vane AIRS Science Team meeting 15 April 2008
Outline: 1. Quick CloudSat overview and project status 2. Standard products 3. CloudSat/AIRS comparisons and complementarity 4. Planned ‘enhanced’ products 5. Summary
CloudSat: A brief overview and status Two main components of design 1. Formation with the A-Train = a multi-platform observing system 2. The Cloud Profiling Radar (CPR) •Nadir pointing, 94 GHz radar 500m • 3.3 µ s pulse 480m vertical res, over- sampled at ~240m • 1.4 km horizontal res. • Calibration better than 2 dBZ ~1.4 km • Sensitivity ~ -28 dBZ (-31 dBZ) • Dynamic Range: 80 dB Hardware continues to operate with nominal performance on ‘Side A’ Prime Mission accomplished Feb 08 CloudSat approved to operate through FY11
CloudSat Data Distribution Summary (As of 1/31/08) 47 Countries (Alphabetical) Product Files Data Volume (Tbytes) 1 Argentina CloudSat Internal Users 421,204 22.1 2 Australia 3 Austria External Users 961,881 51.1 4 Brazil 5 Cameroon Total 1,383,085 73.2 6 Canada 7 Chile 8 China Top External Users by Center (>5000 files) Country 9 Columbia Jet Propulsion Laboratory United States 10 Cost Rica NASA United States 11 Croatia Institute of Atmospheric Physics China 12 Czech Republic Tohoku University Japan 13 Ecuador Kyoto University Japan 14 Ethiopia 15 Finland ICARE / LOA France 16 France NRL United States 17 Germany University of Washington United States 18 Greece University of Miami United States 19 India Max-Planck-Institut f. Meteorology, Hamburg Germany 20 Indonesia TRMM United States 21 Iran 22 Israel NASA Langley NASA / SAIC United States 23 Italy NASA GSFC United States 24 Japan University of Science and Technology China 25 Malaysia Lanzhou University China 26 Nigeria Chalmers University of Technology Sweden 27 Norway Peking University China 28 Pakistan 29 Peru University of Maryland United States 30 Poland Nanjing University Information Science and Technology China 31 Portugal Florida State University United States 32 Puerto Rico Meteorological Service of Canada Canada 33 Qatar University of Bologna Italy 34 Russia 35 Scotland University of Washington United States 36 Singapore Seoul National University South Korea 37 South Africa NICT, JAPAN Japan 38 South Korea EAPRS Lab. De Montfort University United Kingdom 39 Spain California Institute of Technology United States 40 Sweden National Institute of Information and Communications Technology Japan 41 Switzerland 42 Taiwan University of Bonn Germany 43 Thailand NASA Langley Research Center United States 44 The Netherlands Osaka Prefecture University Japan 45 Turkey Texas A and M University United States 46 United Kingdom University of Wisconsin - Madison United States 47 United States
CloudSat Standard & Enhanced Products Standard Description Standard Description Product ID Product ID Level 1 (Since 2 June 2006) Auxiliary Data Products (Since 2 June 2006) Level 1 (Since 2 June 2006) 1A-AUX Auxiliary data for navigation 1A-AUX Auxiliary data for navigation MODIS-AUX MODIS radiances and cloud altitude assignments, raw altitude assignments, raw mask products CPR data CPR data AN-MODIS MODIS 1B radiances and 2B 1B-CPR Calibrated radar reflectivities products subsetted about the (RELEASED) CloudSat footprint Level 2 (Since 2 June 2006, AN-SSF CERES Single Satellite Except 2B-GEOPROF-LIDAR) Footprint (SSF) products 2B-GEOPROF Cloud geometric profile – matched to CloudSat ground (RELEASED) includes a cloud mask (with track confidence measure), AN-state Subset along track of various reflectivity (significant variables forecast model state echoes), (gas) attenuation variables, energy fluxes, etc., correction, and MODIS mask Enhanced Products (In Development) 2B-GEOPROF- Merged radar and lidar cloud 2B-rain Surface rainrate, profiles of LIDAR masks Precipitation liquid water content in (IN DEV.) (liquid) precipitation 2B-CLDCLASS 8 classes of cloud type, 2B-snow Profiles of snow particle size (RELEASED) including likelihood of mixed Precipitation distribution parameters and phase conditions (solid) snowfall rate 2B-TAU Cloud optical depth by layer, 2B-CC-ICE Profiles of number (RELEASED) also effective radius (column) concentration, particle size 2B-CWC Cloud liquid water content and ice water content (RELEASED) (2B-LWC) AN-PR TRMM PR reflectivities and rainfall products matched to Cloud Ice water content CloudSat reflectivity and (2B-IWC) rainfall products AN-AMSRE AMSR radiances and 2B-FLXHR Atmospheric radiative fluxes products matched to (RELEASED) and heating rates CloudSat ground track Special Products (available from NRL-Monterey) Level 3 (In Development) TC-CloudSat Hurricane overpass dataset 3B-zonal-mon Zonally averaged 3B-zonal-sea distributions of clouds derived from averaging 2B-geoprof
CloudSat Level 2 product examples Level 1B radar reflectivity Cloud ice water Cloud geometrical profile (cloud mask) Cloud optical depth Atmospheric downwelling flux Cloud classification (cloud type) Cloud liquid water Upwelling flux
CloudSat L2B GEOPROF-Lidar
CloudSat L2B GEOPROF-Lidar Radar 2B-GEOPROF Radar+lidar 2B GEOPROF-Lidar Difference
Zonally-averaged cloud climatologies for collocated AIRS, CloudSat and CALIPSO observations
Joint pdfs of CloudSat- AIRS cloud top height differences as a function of f A
CloudSat - AIRS differences for AIRS v4 and v5 retrievals
Arctic clouds Minimum Extent Time Series New Record Minimum - Sept. 2007 Kay et al., 2008
The A-train provides a unique view of Arctic clouds DJF Low Cloud Maps ISCCP D2 2B-Geoprof-lidar Warren (infrared) (surface obs.)
2007 Western Arctic Cloud Reductions Kay et al., 2008 A-train data reveal dramatic cloudiness reductions, T increases, and RH decreases associated with the 2007 circulation anomalies.
Polar Surface Radiation Affect from Cloud Reduction 2B-Flxhr The 2007-2006 radiation differences could melt ~0.3 m of sea ice or increase ocean mixed layer temperatures by ~2.4 K.
Enhanced product: precipitation occurrence and amount The PIA within a raining column can be estimated by the decrease in surface reflectivity from the clear sky background value: Z sfc PIA Rainfall / Intensity Rain definite Rain probable Rain possible Extremely sensitive detector of rain - ~0.02 mm/hr
COADS comparison
TRMM/CloudSatAMSR-E comparison of precipitation amount
How Often Does it Rain (Over the Oceans) ? The Fraction of Oceanic Clouds That Precipitate DJF The global mean (oceans) value is ~0.13, i.e., on average, about 13 percent of the clouds observed over our oceans at any time are producing rain. Stephens et al., 2008
Global Snowfall Occurrence Sep. 2006-Aug. 2007
Do clouds heat or cool the atmosphere and by how much??
Radar + lidar cloud mask Radar cloud classification AIRS relative humidity
Summary • CloudSat successfully completed the prime mission and is now in extended mission phase. The flight system is healthy and we are optimistic for operations through at least FY11. • All Level 2 products, and several co-located, auxilliary datasets, are released and available. • Level 3 and enhanced products are under development. • CloudSat observations can be used to determine the precision of AIRS-derived clouds in a wide variety of geophysical conditions, and allow comparisons to be made by cloud type. • Given the relatively favorable agreement between CloudSat and AIRS cloud heights, the AIRS swath is useful to supplement the near-nadir climatology from CloudSat. •The intercomparison of A-Train datasets will lead to more reliable global datasets of cloud structure that will reduce the ambiguity in GCM-satellite comparisons.
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