Possible land-use effects on precipitation and lightning characteristics in the Amazon inferred by TRMM

In the last decade, several authors found evidence that deforestation in the Amazon causes a direct impact on spatial and temporal distribution of precipitation through changes in microphysics and vertical structure of the clouds, as well as changes in the electrical activity of storms. The objective of this study is to investigate the role of deforestation and pollution on the precipitation and electrification of deep convective systems. We evaluated 16 years of TRMM Precipitation Radar (PR) and Lightning Imaging Sensor (LIS) over the Amazon Basin. The land-use effects assessed are vegetation cover and pollution from biomass burning and Manaus city. LANDSAT vegetation maps are used to identify forested ad deforested areas, and coincident or nearly coincident observations of TRMM and Aqua/Terra MODIS (Moderate Resolution Imaging Spectroradiometer) aerosol optical depth are also used to assess possible pollution effects on cloud microphysics. Preliminary results show that, in general, warm convection occurs during cleaner aerosol periods while deep (convective and stratiform) convection and lightning occur in more polluted conditions.