Idealized Models for Tropical Climate Dynamics

该项目通过发展和使用理想化模型来研究热带气候动力学的基本问题。 简单的模型之所以令人感兴趣，是因为因果链没有复杂的气候和大气环流模型复杂。 该项目有两个组成部分，第一部分是调查热带外斜压涡旋（基本上是锋面天气系统）与Hadley环流（即热带地区的大规模翻转环流）和热带辐合区（ITCZ，即赤道附近云量和降雨量增加的区域）的相互作用。 研究的主要重点是热带外涡旋对信风和纬向平均热带降水分布的影响。 研究的第二个组成部分涉及将弱温度梯度（WTG）近似应用于大气单柱模型（SCM）的方法学发展。 WTG近似是一个简单的表示，热带大气温度是水平均匀的，因为地转调整过程的事实，这里进行的工作将推进理解的SCMs和观测到的热带大气的行为的近似的影响。 特别是，在何种程度上的SCM可以模拟降水（一个关键的SCM输出）对热带海表温度，表面风速和水平水分平流在一个国家的最先进的气候model.In的依赖除了推进热带气候动力学的科学，该项目有更广泛的影响，通过培训和教育的研究生和博士后研究助理。 此外，将在网上提供在项目过程中开发的软件源代码，供研究界使用。

This project investigates fundamental questions in tropical climate dynamics through the development and use of idealized models. Simple models are of interest because the chains of cause and effect are less intricate than in sophisticated climate and atmospheric circulation models. The project has two components, the firsts of which is an investigation of the interaction of extratropical baroclinic eddies (essentially frontal weather system) with the Hadley circulation (i.e. the large-scale overturning circulations in the tropics) and the intertropical convergence zones (ITCZs, or zones of enhanced cloudiness and rainfall near the equator). The influence of extratropical eddies on the trade winds and the zonally averaged tropical rainfall distribution will be a primary focus of the research. The second component of the research involves development of methodology for applying the weak temperature gradient (WTG) approximation to single column models (SCM) of the atmosphere. The WTG approximation is a simple representation of the fact that tropical atmospheric temperatures are horizontally homogeneous because of the geostrophic adjustment process, and work conducted here will advance understanding of the implications of the approximation for the behavior of SCMs and the observed tropical atmosphere. In particular, the extent to which the SCM can mimic the dependence of precipitation (a key SCM output) on tropical sea surface temperature, surface wind speed, and horizontal moisture advection in a state-of-the-art climate model.In addition to advancing the science of tropical climate dynamics, the project has broader impacts through the training and education of a graduate student and a postdoctoral research associate. In addition, source code for software developed over the course of the project will be made available online for the use of the research community.