AIRS and the GCSS Pacific Cross-section Intercomparison (GPCI): - PowerPoint PPT Presentation

National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California AIRS and the GCSS Pacific Cross-section Intercomparison (GPCI): Evaluating the Physics of Climate Models Joao Teixeira(1), S. Cardoso (NCAR/IDL) and the GPCI Team (1) Jet Propulsion Laboratory California Institute of Technology Pasadena, California, USA AIRS STM meeting, Caltech, April 2008 For more info contact Joao Teixeira at: teixeira@jpl.nasa.gov 1

National Aeronautics and Climate Change and the Water Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California Vapor and Cloud feedbacks IPCC 2007:  “Water vapor changes represent the largest feedback affecting climate sensitivity and are now better understood”  “Cloud feedbacks remain the largest source of uncertainty” Cloud regimes in tropical/sub-tropical regions play a key role 2

GCSS/WGNE Pacific Cross-section Intercomparison National Aeronautics and Space Administration (GPCI) Jet Propulsion Laboratory California Institute of Technology Pasadena, California ISCCP Low Cloud Cover (%) Sea Surface Temperature 302 JJA 1998 300 298 AM2 SST (K) ARPEGE 296 CAM 3.0 GSM0412 294 HadGAM 292 RAC GME 290 288 -1 2 5 8 11 14 17 20 23 26 29 32 35 latitude (degrees) GPCI is a working group of the GEWEX Cloud System Study (GCSS) – funded by the NASA MAP Program Models and observations are analyzed along a transect from stratocumulus, across shallow cumulus, to deep convection Models: GFDL, NCAR, UKMO, JMA, MF, KNMI, DWD, NCEP, MPI, ECMWF, BMRC, NASA/GISS, UCSD, UQM, LMD, CMC, CSU, GKSS 3

National Aeronautics and GPCI Motivation Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California To study important physical regimes and transitions: stratocumulus,  shallow cumulus and deep convection To evaluate models and observations in the tropics and sub-tropics in  terms of the atmospheric hydrologic cycle To utilize a new generation of satellite datasets (e.g. AIRS)  To help the development of new cloud, convection and turbulence  parameterizations in climate/weather models To create a database of models and observations for future studies of  the tropics and sub-tropics 4

Cloud Cover along GPCI National Aeronautics and Space Administration Jet Propulsion Laboratory AM2 CAM 3.0 California Institute of Technology cloud cover (%) cloud cover (%) Pasadena, California 100 100 pressure (hPa) pressure (hPa) 200 200 J J 300 300 9 J J A A 400 400 8 500 500 7 1 1 600 600 9 9 6 9 9 700 700 5 8 8 800 800 4 900 900 3 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 2 1 0 Large differences in Boundary Deep convection clouds between models 9 layer clouds clouds 8 7 NCEP G&M3 6 ECMWF cloud cover (%) 5 cloud cover (%) 4 100 100 3 200 pressure (hPa) pressure (hPa) 200 J J 300 2 300 J J 400 A 1 A 400 500 500 0 1 1 600 9 600 9 9 9 700 700 8 8 800 800 900 900 1000 1000 5 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 latitude (degrees)

GPCI mean relative humidity – JJA 2003 National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California NCARv2 GFDL METOFF relative humidity (%) relative humidity (%) relative humidity (%) 100 100 100 pressure (hPa) 200 pressure (hPa) 200 pressure (hPa) 200 J J J 300 300 300 J J J A A A 400 400 400 500 500 500 2 2 2 600 600 600 0 0 0 0 0 0 700 700 700 3 3 3 800 800 800 900 900 900 1000 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 latitude (degrees) latitude (degrees) latitude (degrees) AIRS relative humidity (%) 90 90 100 80 80 200 pressure (hPa) 70 70 J 300 J 60 60 400 A 50 50 500 40 40 2 600 30 30 0 0 20 20 700 3 10 10 800 0 0 900 1000 -1 2 5 8 111417202326293235 6 latitude (degrees)

Relative humidity differences: model- AIRS (JJA03) National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California GFDL - AIRS NCARv2 - AIRS METOFF - AIRS relative humidity (%) relative humidity (%) 100 relative humidity (%) 75 100 100 100 50 40 200 200 200 pressure (hPa) pressure (hPa) pressure (hPa) 30 J J J 300 300 300 20 J J J 400 A 400 A 10 400 A 5 500 500 500 2 2 2 0 600 600 600 0 0 0 -5 0 0 -10 0 700 700 700 3 3 3 -20 800 800 800 -30 900 900 -40 900 -50 1000 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 -75 -1 2 5 8 111417202326293235 AIRS latitude (degrees) latitude (degrees) -100 latitude (degrees) relative humidity (%) 100 90 200 80 pressure (hPa) J 300 70 J 60 400 A UKMO PBL is Models are 50 500 2 40 deeper and/or much drier 600 0 30 0 700 moister/colder above Sc: AIRS 20 3 800 10 sampling …? 900 0 1000 -1 2 5 8 111417202326293235 7 latitude (degrees)

Model RH only for TCC < 70%: model- AIRS (JJA03) National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California NCARv2 - AIRS METOFF - AIRS relative humidity (%) relative humidity (%) 100 100 75 100 50 200 200 pressure (hPa) pressure (hPa) 40 J J 300 300 30 J J 20 400 A 400 A 10 500 500 2 5 2 Moist biases 600 0 600 0 0 0 -5 0 700 700 decrease 3 -10 3 800 800 -20 900 900 -30 Dry biases -40 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 -50 increase (tropics) -75 latitude (degrees) latitude (degrees) NCARv2 - AIRS -100 METOFF - AIRS TCC 70% relative humidity (%) TCC 70% relative humidity (%) 100 100 200 pressure (hPa) 200 pressure (hPa) J J 300 300 J J 400 A 400 A 500 500 2 2 600 0 600 0 0 700 0 700 3 Slightly smaller 3 800 800 bias above Sc 900 900 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 8 latitude (degrees) latitude (degrees)

National Aeronautics and AIRS and models relative humidity standard deviation Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California NCARv2 GFDL METOFF TCC 70% relative humidity STDev (%) TCC 70% relative humidity STDev (%) TCC 70% relative humidity STDev (%) 100 100 100 pressure (hPa) 200 pressure (hPa) 200 pressure (hPa) 200 J J J 300 300 300 J J J A A A 400 400 400 500 500 500 2 2 2 600 600 600 0 0 0 0 0 700 700 0 700 3 3 3 800 800 800 900 900 900 1000 1000 1000 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 -1 2 5 8 111417202326293235 latitude (degrees) latitude (degrees) latitude (degrees) AIRS relative humidity STDev (%) 100 90 UKMO variability 80 200 pressure (hPa) J 70 300 is very different J 60 400 A from AIRS, NCAR 50 500 40 2 and GFDL 600 0 30 0 700 20 3 10 800 0 900 1000 -1 2 5 8 111417202326293235 latitude (degrees) 9