African Easterly Waves and Their Interactions with Clouds and Convection

认识到非洲东风波（AEWs）在从日常到季节性预报中的重要作用，本项目试图了解非洲东风波的演变及其与对流的相互作用。研究的第一部分是在预警系统生命周期的各个阶段获得这些相互作用的统计关系，并利用ECMWF的分析、卫星数据、无线电探空数据和雨量计数据调查其中涉及的物理过程。然后，通过个案研究的方法，跟踪个别预警系统的演变及其与对流的相互作用，加强研究。第三部分，尽管优先级较低，是调查AEWs、非洲东风急流和热带对流之间存在的关系的季节内到年际变化。一个重要的目标是通过预警系统和热带对流的相互作用来了解和获取大西洋热带气旋的前兆。如果能建立一个热带气旋形成的概念模式，将对预测界有很大的价值。项目积极参与计划在2004/2005年举行的国际西非季风（WAM）试验。这项资助的研究将有助于WAM现场实验的规划。

Recognizing the important role the African easterly waves (AEWs) play in forecasts ranging from daily to seasonal, this project seeks to understand the evolution of AEWs and their interactions with convection. The first part of the research is to obtain the statistical relationships in these interactions at various phases in the life cycle of AEWs and to investigate the physical processes involved in them using the ECMWF analyses, satellite data, radiosonde data and raingauge data. The study will then be enhanced through a case-study approach following the evolution of individual AEWs and their interactions with convection. The third part, albeit at a lower priority, is to investigate the intra-seasonal to inter-annual variability of the relationships that exist between the AEWs, the African easterly jets, and tropical convection. An important goal is to understand and gain knowledge of the precursors of Atlantic tropical cyclones through the interactions of the AEWs and tropical convection. If a conceptual model can be developed for the preconditioning for tropical cyclogenesis, it would be very valuable for the prediction community. The PI is actively involved in planning the international Western African Monsoon (WAM) experiment to be held in 2004/2005. The research from this grant will contribute to the planning of the WAM field experiment.