A vertical transport window of water vapor in the troposphere over the Tibetan Plateau with implications for global climate change

Xiangde Xu,Hongxiong Xu,Bin Chen,Shengjun Zhang,Chan Sun,Jianjun Xu,Xiaoyun Sun,Yan Zhu,Tianliang Zhao,Deliang Chen,Yang Zhao,Juan Li,Lili Dong

doi:10.5194/acp-22-1149-2022

Abstract

Abstract. By using the multi-source data of meteorology over recent decades, this study discovered a summertime “hollow wet pool” in the troposphere with a center of high water vapor over the Asian water tower (AWT) on the Tibetan Plateau (TP), which is indicated by a vertical transport “window” in the troposphere. The water vapor transport in the upper troposphere extends from the vertical transport window over the TP with significant connections among the Arctic, Antarctic and TP regions, highlighting the effect of the TP's vertical transport window of water vapor in the troposphere on global change in water vapor. The vertical transport window is built by the AWT's thermal forcing in association with the dynamic effect of the TP's “hollow heat island”. Our study improves the understanding of the vapor transport over the TP with important implication for global climate change.

Highlights

The Tibetan Plateau (TP) is the largest extent of high terrain in the world, known as “the roof of the world”, with an average altitude of over 4000 m
The following questions are of great concern in the TP vertical transport of water vapor study with implications for global change, for example: what is the formation mechanism of the vertical transport window of water vapor in the troposphere on the TP? How is the vertical transport of water vapor in the troposphere constructed with the special column of an apparent heat source in the Asian water tower” (AWT) over the TP? What is the global effect of the vertical transport window of water vapor in the troposphere on the TP? From the perspective of global atmospheric energy and water vapor exchanges, this study characterizes a window of water vapor vertical transport within the troposphere over the TP and implications for global change
It is worth noting that the fraction of the total cloud that comprises strong convective clouds ranges from 4.0 % to 21.0 % in the TP, and during the summer season the thermal forcing of the TP is dominated by the latent heat released by cloud and precipitation (Fu et al, 2006; Dessler et al, 2006; Gao et al, 2014)

Summary

Introduction

The Tibetan Plateau (TP) is the largest extent of high terrain in the world, known as “the roof of the world”, with an average altitude of over 4000 m Several rivers, such as the Yangtze, Yellow River, Lancang River and Ganges, originate from the TP, which is regarded as the “Asian water tower” (AWT) (Xu et al, 2008). Many studies have been focused on the transport of water vapor into the upper troposphere and lower stratosphere from the tropical oceans to the high-altitude TP (Chen et al, 2012; Wang et al, 2017; Xie et al, 2018; Randel et al, 2013). The following questions are of great concern in the TP vertical transport of water vapor study with implications for global change, for example: what is the formation mechanism of the vertical transport window of water vapor in the troposphere on the TP? How is the vertical transport of water vapor in the troposphere constructed with the special column of an apparent heat source in the AWT over the TP? What is the global effect of the vertical transport window of water vapor in the troposphere on the TP? From the perspective of global atmospheric energy and water vapor exchanges, this study characterizes a window of water vapor vertical transport within the troposphere over the TP and implications for global change

Data and methods

The structures of vertical transport window of water vapor over the TP

Global effect of the vertical transport window over the TP

The transport window of water vapor driven by the AWT

Conclusions