HR: 08:30h
AN: A51F-04    [Abstracts]
TI: Tropical Large-Scale Circulations : Asymptotically Nondivergent ?
AU: * MULET, S
EM: muletsandrine@yahoo.fr
AF: Laboratoire de Meteorologie Dynamique du CNRS, Universite de Paris 6, 4 place Jussieu, Tour 45-55 3eme BP 99, Paris, 75005, France, Metropolitan
AU: YANO, J
EM: jun-ichi.yano@meteo.fr
AF: CNRM-GAME, Meteo-France, 42 av Gaspard Coriolis, Toulouse, 31057, France, Metropolitan
AU: BONAZZOLA, M
EM: Marine.Bonazzola@lmd.jussieu.fr
AF: Laboratoire de Meteorologie Dynamique du CNRS, Universite de Paris 6, 4 place Jussieu, Tour 45-55 3eme BP 99, Paris, 75005, France, Metropolitan
AB: The large-scale tropical atmospheric flows are overall in balance between the diabatic heating associated with deep convection and the vertical advection to the leading order in the thermodynamic equation (cf., Sobel et al., 2001). Moreover, a simple scale analysis implies, under this thermodynamic balance condition, that the tropical large-scale circulations are more dominated by vorticity than divergence. The present work considers the tendency of the tropical large-scale circulations to asymptotic non divergence by analyzing data from the TOGA COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment). We consider the evolution of divergence and vorticity during the TOGA COARE period with regard to the passage of a Madden Jullian oscillation (MJO). We quantify the non divergence tendency by a statistical analysis comparing divergence and vorticity. A scatter plot between divergence and vorticity shows that, at 850mb, divergence is less important than vorticity. Finally, we study the space and time scale dependence of the asymptotic tendency for non divergence.
DE: 3319 General circulation (1223)
DE: 3364 Synoptic-scale meteorology
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting