Convective systems structure over Southeastern South America using TRMM observations.

PAOLA SALIO; LUCIANO VIDAL; EDWARD ZIPSER; CHUNTAO LIU

7 – 11 de Julio. Cancún. Mexico

Congreso; 15th International Conference on Clouds and Precipitation.; 2008

IAMMAS

Global and regional characteristics of deep convection over South America have been analyzed by many authors based on different observing tools. Satellite infrared images have been the primary tool since the GOES constellation satellite was launched over the region. These data make it possible to understand the evolution and behavior of convective systems over many regions, especially over large areas without ground-based observations. Based on geostationary satellite information, Machado et al (1998), Velasco and Frisch (1987), among others showed the characteristics and structure of mesoscale convective systems over South America. However, there is an important lack of knowledge of the internal structure of convective systems over the area due to the sparse ground-based radar network.   The Tropical Rainfall Measuring Mission (TRMM) constellation (Kummerow et al., 1998) measures visible and infrared radiances (VIRS), microwave radiance from TRMM Microwave Imager (TMI), radar reflectivity from the Precipitation Radar (PR), and flashes from Lightning Imager Sensor (LIS). This unique dataset provides the opportunity to investigate the internal structure of convection mainly over tropical and subtropical areas and to describe the evolution of its diurnal cycle.   A prime motivation of this study is to generate a climatology and characterize the internal structure of the convection over Southeastern South America (SESA). This paper also describes the diurnal cycle of convection over SESA and the relationship between the internal structure of convection and different synoptic situations dominated by low level jets (LLJs).