Distinct impacts of vapor transport from the tropical oceans on the regional glacier retreat over the Qinghai-Tibet Plateau

Abstract

An influence of precipitation on the glacier changes over the Qinghai-Tibet Plateau (QTP) is investigated in this paper. The results show that the glacial loss rates of glaciers in the QTP are significantly correlated with the interannual changes of precipitation and low cloud cover. The water vapor, importing with the warm and wet airflows from the Asian Monsoon regions, significantly influence the precipitation in the southern and northern glacier areas of the QTP in the summer monsoon season. The three-dimensional changes of water vapor transport can lead to the difference of water balance between different glacier areas. Under global warming, the northwest QTP is in the ascending branch of the vertical water driven thermally by the tropical Indian Ocean. The warm water vapor from the tropical ocean climbs to the QTP, forming a significant supply effect of precipitation in the northwestern glacier area, which makes the glacier retreat at a relatively slow rate. Meanwhile, the southern and southeastern QTP regions are in the descending branch of vapor transport with the declining trend in the lower troposphere, which lead to the shortage water supply aggravating the glacier loss in the southern and southeastern QTP.