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Direct comparison of meteosat water vapor channel data and general circulation model results
Author(s) -
Roca Rémy,
Picon Laurence,
Desbois Michel,
Le Treut Hervé,
Morcrette JeanJacques
Publication year - 1997
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl03923
Subject(s) - troposphere , climatology , environmental science , convection , water vapor , subtropics , atmospheric sciences , intertropical convergence zone , moisture , general circulation model , circulation (fluid dynamics) , meteorology , geology , precipitation , climate change , oceanography , geography , physics , mechanics , fishery , biology
Following a model to satellite approach, this study points out the ability of the general circulation model (GCM) of the Laboratoire de Météorologie Dynamique to reproduce the observed relationship between tropical convection and subtropical moisture in the upper troposphere. Those parameters are characterized from Meteosat water vapor equivalent brightness temperatures (WVEBT) over a monthly scale. The simulated WVEBT field closely resembles to the observed distribution. The pure water vapor features and the convective areas are well located and their seasonal variations are captured by the model. A dry (moist) bias is found over convective (subsiding) areas, whereas the model globally best acts over Atlantic ocean than over Africa. The observed and simulated seasonal variations show that an extension of the ITCZ is correlated to a moistening of the upper troposphere in subtropical areas. Those results imply a positive large scale relationship between convective and subsiding areas in both observation and simulation, and suggest the relevance of our approach for further climatic studies.