An investigation of the annual cycle of convective activity over the tropical Americas

Outgoing longwave radiation (OLR) is used to describe the annual cycle of convection that resides over the Amazon Basin during austral summer and over Central America and the adjacent waters of the Pacific during austral winter. The preferred locations of the convective during the wet season in the respective hemispheres are determined, and the beginning and ending of these seasons is specified. Analyses produced by the European Centre for Medium-range Weather Forecasts are superimposed upon OLR fields to illustrate features of the atmospheric circulation in the vicinity of the tropical Americas that are associated with the annual cycle of convection. The onset and demise of the wet season in the Amazon Basin are further described by means of composites of these data.