Synoptic climatology of tropical and subtropical South America and adjoining seas as inferred from Geostationary Operational Environmental Satellite imagery

Abstract

Three-hourly infrared, visible and water vapour channel satellite imagery from the Geostationary Operational Environmental Satellite for the 15-year period 2003–2017 is processed to obtain a climatology for the South American region. All major features such as the Intertropical Convergence Zones, the South Atlantic Convergence Zone, the Amazon Basin convection, the Atacama Desert and the Northeast Brazil semiarid region are well delineated. Seasonal migrations and shifts of cloud systems are obtained. The study reveals the precise locations and extents of convective regions associated with large scale permanent and semi-permanent features. The double Intertropical Convergence Zone in eastern equatorial Pacific is discussed. Some hitherto unnoticed and little discussed features such as the coastal cloud inhibition near the southeastern Brazil region and a conspicuous convective region near the coast of the state of Para are found. The dynamical reasons for the formation of these features are postulated. This climatology should serve to validate different climate-scenario models and Numerical Weather Prediction models, besides providing guidance to operational meteorologists of the region.