Collaborative Research: The Dynamics of Water Vapor in the Tropics

这项合作项目将与迈阿密大学的张赤东博士合作，涉及对热带对流层上层水汽观测到的双峰分布的调查。主要研究人员将设法确定双峰现象的起源及其对大规模热带环流的影响。水蒸气可以通过辐射效应在大气动态中发挥重要作用，甚至在大气中最干燥的部分也是如此。同时，通过对流云输送的水汽是对流层上层水汽的来源，伴随着潜热的释放。水汽对环流的影响在热带多云对流区域和非饱和区域之间有很大的不同。主要研究人员将进行观察性和模型性研究。第一部分将包括对水汽双峰的规模、位置和时间依赖性的调查，以及对造成观测到的分布的潜在机制的分析。在模拟工作中，将使用一个简单的机制模式和一个大气环流模式来评估对热带环流的影响。

This collaborative project will be undertaken with Dr. Chidong Zhang of the University of Miami and involves an investigation into the observed bimodal distribution of water vapor in the tropical upper troposphere. The principal investigators will seek to identify the origins of the bimodality and the implications for the large-scale tropical circulations. Water vapor can play a major role in the dynamics of the atmosphere, even in the driest parts of the atmosphere, through radiative effects. At the same time, moisture transported through convective clouds is a source of moisture, accompanied by latent heat release, in the upper troposphere. The impact of water vapor on the circulation differs substantially between cloudy, convective regions of the tropics and unsaturated regions. The principal investigators will pursue both observational and modeling studies. The first will include a survey on the scale, location, and time dependence of the water vapor bimodality and analysis of potential mechanisms responsible for the observed distribution. In the modeling work, both a simple mechanistic model and an atmospheric general circulation model will be used to assess the impact on the tropical circulation.