Observation of cold pools in the Amazon

The cloud cover over the Amazon region in a 9 x 9 degree square, centered at SW Amazon is analyzed for 6 weeks during the TRMM/LBA Experiment to identify cold pools. VIS channel was used because of its high spatial resolution allowing reliable cumulus cloud identification, in spite of the unavailability of night information.

Previous inspection of radar and visible satellite imagery for the above period and subsequent monitoring of satellite imagery over the region, suggests that cold pools produced by precipitation driven downdrafts is quite common over the Amazon. Preliminary results suggest that in 70% of the days analyzed, cold pools are observed in the study area. Complementary observations from the SPOL radar deployed during the campaign was used to better define the corresponding cold pool through the gust front, provide that they are in the same area.

The surface cold pool identification is of paramount importance since the pools have a substantial impact on the spatial organization of convection. This distribution of convection in space, by its turn, affects the convective transport of heat, momentum and moisture.

Presently this study is being extended to cover one year of data. Also, a possible relationship with the prevalent wind regime in the region is being investigated.