The South Atlantic Convergence Zone: a critical view and overview

Abstract

The South Atlantic Convergence Zone (SACZ) is an elongated and persistent band of convection which in the summer season and fairly frequently extends itself from the Amazon to the ocean offshore the Brazilian coasts, playing a significant role in the country´s rainfall regime. Together with its twins in the Pacific and Indian, it makes up a new category of large-scale meteorological organisms, identified from the 1970s through the analysis of satellite observations. The explanation for the phenomenon is still a challenge to meteorology and climatology; essentially, it results from an intense interaction between tropical and mid-latitude systems. In this paper, we review a part of the subject´s history, including, besides Brazilian researchers´s contributions, the providential Japanese studies comparing the SACZ with the Baiu, and present brief descriptions of SACZ events in Brazil. As a complement, we report ourselves to two events of destructive intense precipitation, of frontal nature, in São Paulo state, to be compared to SACZ action.