P2.2
Cloud-topped boundary layer simulations with a single-column GCM
Sylvain Cheinet, Laboratoire de Meteorologie Dynamique, Paris, France; and Z. X. Li and H. Le Treut
LMD GCM, among others, tends to underestimate the low cloud cover over anticyclonic areas, where subgrid (parameterized) processes strongly interact.
The presented work is an attempt to assess this non-prediction, through the analysis of the coupling between parameterizations used in the LMD GCM. A single-column version of the GCM (with larger vertical resolution) is used to approach the interactions and their sensitivity to some parameters. The initialization profile corresponds to a situation where stratocumuli where observed (ASTEX campaign data).
The interactions between turbulence, convection and radiation schemes will be discussed in the context of ASTEX observations. It will be shown that in spite of the crude parameterizations, some characteristics of the observed evolution of the PBL are found to be simulated. Sensibility tests and differences between observations and simulations will also be pointed out, in order to discuss about possible improvements of the present code.
Poster Session 2, Cloudy
Wednesday, 9 August 2000, 6:00 PM-9:00 PM
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