Early results from TRMM-LBA: Kinematic and microphsical characteristics of convection in distinct meteorological regimes

The Amazon basin represents the interior of a tropical continent where heavy seasonal rainfall occurs. This precipitation regime represents the most important unsampled tropical rainfall regime for the purposes of TRMM. Dual radar (one dual-polarized) and sounding observations from TRMM/LBA provide a valuable backdrop for specialized observing systems, namely, the NASA ER-2 aircraft, the Citation II aircraft equipped with microphysics instrumentation, a lightning network, multiple rain gauge networks, a dual-wavelength profiler, tethersondes and flux instrumentation. Key objectives of TRMM/LBA centered on validation of TRMM satellite algorithms and validation of numerical cloud models utlized to obtain 4-D diabatic heating from TRMM observables. In this abstract we report on early results from the field campaign emphasizing characteristics of the convection observed by ground based radar as a function of meteorological regime.

Two primary meteorological regimes were observed during TRMM/LBA: a wet, monsoon-like regime in which the vertical structure of convection resembled that observed in oceanic/monsoon climates, and a dryer break-like regime in which the convection was characteristically more continental-like, exhibiting robust vertically development and significant electrification. Set in the framework of the large-scale forcing responsible for the two regimes, we will contrast the kinematic and microphysical characteristics of "monsoon" and "break" period convection utilizing both dual-Doppler and multiparameter radar analyses.