HR: 08:00h
AN: A31D-01 INVITED     [Abstracts]
TI: Insights into East Pacific ITCZ convection from EPIC observations and cloud-resolving modeling
AU: * Bretherton, C S
EM: breth@atmos.washington.edu
AF: Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195-1640, United States
AU: Blossey, P N
EM: bloss@atmos.washington.edu
AF: Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195-1640, United States
AB: During the EPIC 2001 project, a wealth of airborne and ship-based measurements (including a continuous scanning precipitation radar and vertically-pointing cloud radar) were made in a mesoscale region around 10 N, 95 W. Several studies based on this data have documented the vertical and horizontal structure of the convection and its connection to surface wind speed, convective inhibition, and easterly waves. Lower-tropospheric humidity, surface latent heat fluxes and mesoscale SST variability have been suggested as primary drivers modulating area-averaged rainfall over this area. We present the first EPIC cloud-resolving model (CRM) simulations of the EPIC ITCZ study area. These can be compared with the whole suite of atmospheric observations and allow exploration of the correlation of rainfall with the hypothesized drivers. We compare simulations conventionally forced with specified horizontal advection and vertical motion with ‘weak-temperature gradient' simulations in which the vertical motion is chosen to maintain the observed tropospheric temperature, and simulations including mesoscale SST variability, and use these to test and enhance our understanding of the thermodynamic control of ITCZ convection in the east Pacific.
DE: 3311 Clouds and aerosols
DE: 3314 Convective processes
DE: 3337 Global climate models (1626, 4928)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly