CONICET | Buscador de Institutos y Recursos Humanos

The continent of South America exhibits a distinct geomorphology, with a large tropical land mass and the Andes cordillera that effectively blocks moisture advection from the Pacific Ocean. Surface conditions vary greatly both in the zonal and meridional direction, giving regional character to the seasonality and distribution of precipitation regimes. The latter are also influenced by remote forcings from the adjoining oceans in a variety of time scales. As a result, the monsoonal circulation (SAMS) and summer rains over this continent present distinctive features to be reviewed in this lecture. One such feature is the South Atlantic Convergence Zone (SACZ), a convection band that extends from the north-west to the south-east from the core of the continent and into the Atlantic Ocean. This is a complex phenomenon with different character over the land and the ocean, and with oscillations that link the deep tropics to subtropical latitudes of South America. The lecture will review and give an update of current knowledge on these topics. Emphasis will also be placed in the ability of 20th-century climate simulations to reproduce the SAMS and the SACZ as a first step to evaluate the credibility of models under climate change scenarios. Projections for the 21st- century indicate an increase of summer precipitation over southeastern subtropical South America, and though models seem to reproduce the main features of the SAMS and the SACZ, deficiencies in simulation of their variability are noted. The subject aligns itself with the main topic of this conference Climate and Water in the Southern Hemisphere, with a focus in a continent that strongly depends on water to support its energy and industry needs.

enviar mensaje