Analysis and Simulation of the Seasonal Variation of the Atmospheric Circulation Over Tropical South America

本文提出的研究目的是描述热带南美洲附近对流降雨的年循环，并阐明产生对流降雨的因素。对对流型年周期的描述将利用极地轨道卫星在1979-1985年期间测量的出射红外辐射来完成。热带环流型态的相关变化将从对垂直6个高度的风和其他参数的客观分析中得出。还将研究这7年期间热带南美洲上空对流和大气环流的季内和年际变化。提出的研究的另一个目标是开发和使用一个相对简单的数值模型来研究相对于赤道不同形状和位置的对流热源的动力学响应。这项工作很重要，因为它将增强我们对热带大陆对流在维持大尺度大气环流中的作用的理解。

The objective of the research proposed here is to describe the annual cycle of convective rainfall in the vicinity of tropical South America and to elucidate the factors which are responsible for producing it. Description of the annual cycle of convective patterns will be accomplished using outgoing infrared radiation measured from polar orbiting satellites for the period from 1979-1985. Accompanying changes in tropical circulation patterns will be derived from objective analyses of wind and other parameters at 6 levels in the vertical. Intraseasonal and interannual variations in the convection and atmospheric circulation over tropical South America during this 7 year period will also be investigated. A further objective of the proposed research is the development and use of a relatively simple numerical model for studying the dynamical response to convective heating sources of various shapes and locations relative to the equator. This work is important because it will enhance our understanding of the role of tropical continental convection in maintaining large scale atmospheric circulation.