Collaborative Research: The Dynamics of Water Vapor in the Tropics

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

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.