HR: 0800h
AN: A41C-0056    [Abstracts]
TI: Using a METEOSAT Water Vapor database for the evaluation of general circulation models over tropical areas
AU: Roca, R
EM: roca@lmd.ens.fr
AF: Laboratoire de Meteorologie Dynamique, 4 place Jussieu, Paris, 75005 France
AU: * Brogniez, H
EM: hbrogniez@geosci.uchicago.edu
AF: Department of the Geophysical Sciences The University of Chicago, 5734 S. Ellis Ave., Chicago, IL 60637 United States
AU: Picon, L
EM: laurence.picon@lmd.polytechnique.fr
AF: Laboratoire de Meteorologie Dynamique, 4 place Jussieu, Paris, 75005 France
AB: In this work, a database of free tropospheric humidity (FTH) derived from METEOSAT "Water Vapor" observations and spanning the 1984-1995 period are used to evaluate 14 climate models in the frame of the Atmospheric Model Intercomparison Project (AMIP) phase 2. The methodology follows a two step "model-to-satellite" approach, by simulating first the METEOSAT-5 "Water Vapor" equivalent brightness temperatures (BT) from the model profiles and the RTTOV-7 radiative code, and, second, by converting the BTs into FTH using the same coefficients as in the satellite product for a direct comparison. The analysis is focused on the dry subtropical areas observed by METEOSAT: the Eastern Mediterranean and the tropical South Atlantic Ocean. Most of the models reproduce the observed seasonal cycle both in terms of phasing and magnitude, despite an overall moist bias. A few models are in close agreement with the satellite data. The magnitude of the satellite estimated inter-annual variability is also generally captured by models. Again, a small subset of models shows close agreement with the observations. This comparison suggests general improvements of the models with respect to the AMIP-1 simulations.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3337 Global climate models (1626, 4928)
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005