HR: 0800h
AN: A21C-0639    [Abstracts]
TI: Using COAMPS Microphysics To Model Satellite and Aircraft Radar Data: An Evaluation During Hurricane Dennis
AU: * Chen, S
EM: sue.chen@nrlmry.navy.mil
AF: Naval Research Laboratory, Marine Meteorology Division 7 Grace Hopper Avenue, Monterey, CA 93943, United States
AU: Turk, J
EM: joe.turk@nrlmry.navy.mil
AF: Naval Research Laboratory, Marine Meteorology Division 7 Grace Hopper Avenue, Monterey, CA 93943, United States
AB: The field phase of the Tropical Cloud Systems and Processes (TCSP) experiment took place between 1-27 July 2005, based out of San Jose, Costa Rica. Although the focus area for TCSP was planned to be the Eastern Pacific, the unusually early genesis of tropical disturbances in the Eastern Caribbean prompted missions dedicated to the formation and evolution of Hurricane Dennis. The high-altitude (20-km) NASA ER-2 flew 12 missions, including three dates dedicated to Hurricane Dennis. The flights on July 5-6 captured Dennis as it was transitioning from a tropical storm to a hurricane, and July 9 as it was entering a period of rapid intensification. The ER-2 deployed three microwave sensors, the Advanced Microwave Precipitation Radiometer (AMPR), the High Altitude MMIC Sounding Radiometer (HAMSR) and the the ER-2 Doppler Radar (EDOP). The AMPR is the aircraft "simulator" of the TRMM sensor; from 20-km altitude its 85 GHz imagery has an on-Earth resolution of 700-m (2.8-km at 10 GHz) at nadir, nearly 20 times finer than typical TRMM or SSMI satellite imagery. EDOP is an 10 GHz Doppler radar capable of resolving the fine scale vertical reflectivity. Since microwave observations respond to the presence of water vapor, liquid and ice hydrometeors, they are useful for evaluating the capabilities and deficiencies of mesoscale prediction models in representing the spatial evolution of the underlying cloud structure. In this presentation, the microphysical outputs from simulation of Hurricane Dennis using the Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS) were used to forward model observed TRMM and SSMI satellite data, and the AMPR, HAMSR and EDOP data from the ER-2 aircraft overpasses. This allows model-vs- observation diagnostics to be performed in observational space, avoiding usage of retrieved satellite quantities. Statistical intercomparisons show model overpredictions of the reflectivities at upper levels, and an overprediction of the coldest 85 GHz brightness temperatures reflecting excessive graupel. Although the results are limited to a single case, the methodology is potentially adaptable to routine COAMPS model runs for analyzing modifications to microphysical parameterization schemes.
UR: http://camex.nsstc.nasa.gov/tcsp/
DE: 0320 Cloud physics and chemistry
DE: 0360 Radiation: transmission and scattering
DE: 3329 Mesoscale meteorology
DE: 3374 Tropical meteorology
DE: 3394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting