Collaborative Research: The Dynamics of Water Vapor in the Tropics

该合作项目将与迈阿密大学的张赤东博士合作，研究热带对流层上层水汽的双峰分布。主要研究人员将设法确定双峰的起源及其对大尺度热带环流的影响。水蒸气可以通过辐射效应在大气动力学中发挥重要作用，即使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的水汽来源，并伴有潜热释放。水汽对环流的影响在热带的多云对流区和不饱和区有很大的不同。主要研究人员将进行观测和模型研究。第一项工作将包括调查水汽双峰的尺度、位置和时间依赖性，并分析造成观测到的分布的潜在机制。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.