HR: 12:08h
AN: A42C-10 INVITED    [Abstracts]
TI: Evaluating Colorado State University and NASA Goddard multi-scale modeling framework (MMF) representation of tropical cloud and precipitation structures using CloudSat data
AU: * Luo, Z
EM: luo@sci.ccny.cuny.edu
AF: City College of New York, 138 St. and Convent Ave., New York, NY 10031, United States
AU: Chern, J
AF: NASA Goddard Space Flight Center, Mesoscale Atmospheric Processes Branch, Greenbelt, MD 20771, United States
AU: Haynes, J M
AF: Colorado State University, Laporte Ave., Fort Collins, CO 80523, United States
AU: Stephens, G L
AF: Colorado State University, Laporte Ave., Fort Collins, CO 80523, United States
AU: Tao, W
AF: NASA Goddard Space Flight Center, Mesoscale Atmospheric Processes Branch, Greenbelt, MD 20771, United States
AU: Wood, N B
AF: Colorado State University, Laporte Ave., Fort Collins, CO 80523, United States
AB: Two multi-scale modeling frameworks (MMFs) recently developed at Colorado State University (CSU) and NASA Goddard are evaluated against the initial CloudSat radar observations in the simulation of tropical cloud and precipitation structures. Since MMF adopts a first-principle approach to representing the dynamics and physics of cloud-scale processes, model-data comparison becomes more straightforward, especially in characterizing structures of tropical convection and the associated cloudiness. A radar simulator package called QuickBeam is used to convert modeled hydrometeor profiles into radar reflectivities. Furthermore, novel diagnostic tools and regime classification are used that were recently developed to emphasize the unique nature of the new space- borne active sensors. It is found that both CSU and Goddard MMFs have difficulties in capturing some aspects of the structure and distribution of tropical cloud and precipitation systems. For example, the boundary-layer clouds in CSU MMF are too thick such that they look as if they were drizzling clouds from radar perspective. The Goddard MMF, on the other hand, simulates the drizzle regime that is too deep in vertical extent. For deep convection, both CSU and Goddard MMFs seem to underpredict the large radar echoes at high altitude, suggesting that the simulated deep convective towers do not transport enough large-size particles into the upper troposphere. Regional biases in the two models are also presented.
DE: 1626 Global climate models (3337, 4928)
DE: 3337 Global climate models (1626, 4928)
DE: 4928 Global climate models (1626, 3337)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting