On the South Atlantic Convergence Zone affecting southern Amazonia in austral summer

Time series analysis of the average rainfall over a target area in southern Amazon Basin showed a spectral peak at 11 day period. An objective method for defining the South Atlantic Convergence Zone (SACZ) is used to identify 28 episodes affecting southern Amazon Basin during the 10 summers in the period 19992010. The 28-episode composite precipitation anomalies show significant positive values over the target area. The convergence of moisture over the target area in the SACZ composites is about 35% stronger than the climatological value. Copyright (c) 2012 Royal Meteorological Society