Studies in the Climate Dynamics of Moist Processes

本项目研究热带对流降雨的基本特性及其与大尺度大气条件的复杂关系。 这项工作建立在同一小组以前的工作基础上，该小组发现热带降水的几个重要特性，包括发生频率，方差和强度，当被视为大体积大气水蒸气含量除以与温度相关的临界水蒸气值时，表现出简单的行为。 研究工作分为四个主题：1）水汽、对流及其相互作用的观测约束; 2）与输送过程相关的分布尾部及其含义，特别是对极端降水事件的影响; 3）降水模拟、湿遥相关和对流边缘的问题，4）区域气候问题中降水过程的参数敏感性估计/优化方法。热带对流降水的行为具有巨大的实际意义，作为世界上大部分居住在热带地区的人口的水分来源。 然而，尽管它的重要性，热带对流的性质仍然是神秘的，因为对流降雨是由大尺度大气条件和小尺度对流云的性质之间的复杂相互作用。 在这里进行的研究旨在提高对热带对流及其在天气和气候模式中的代表性的认识，这种改进对面临热带气候变率（包括厄尔尼诺事件）和热带气候变化影响的决策者有很大的潜在好处。

This project examines fundamental properties of tropical convective rainfall and its complex relationship to large-scale atmospheric conditions. The work builds on previous work by the same group which found that several important properties of tropical precipitation including frequency of occurrence, variance, and intensity, show simple behavior when treated as functions of bulk atmospheric water vapor content divided by a critical water vapor value related to temperature-dependent saturation specific humidity. The work is divided into four topics: 1) Observational constraints on representations of moisture, convection, and their interactions; 2) distribution tails associated with transport processes and their implications, particularly for extreme precipitation events; 3) Issues in precipitation simulation, moist teleconnections and convective margins, and 4) Methods for parameter sensitivity estimation/optimization with a focus on precipitation processes in regional climate issues.The behavior of convective precipitation in the tropics is of immense practical importance, as the source of moisture for the large portion of the world's population residing in the tropics. Yet despite its importance the nature of tropical convection remains mysterious, as convective rainfall is governed by complex interactions between large-scale atmospheric conditions and the properties of small-scale convective clouds. Research conducted here seeks to improve understanding of tropical convection and its representation in weather and climate models, and such improvements have great potential benefit for decision makers confronted with the impacts of tropical climate variability (including El Nino events) and tropical climate change.