The Warming and Wetting Ecological Environment Changes over the Qinghai-Tibetan Plateau and the Driving Effect of the Asian Summer Monsoon

The impact of warming and wetting on the ecological environment of the Qinghai-Tibet Plateau(TP) under the background of climate change has been a concern of the global scientific community. In this paper, the optimized interpolation variational correction approach is adopted for the analysis of monthly high-resolution satellite precipitation products and observations from meteorological stations during the past 20 years. As a result, the corrected precipitation products can not only supplement the"blank area"of precipitation observation stations on the TP, but also improve the accuracy of the original satellite precipitation products. The precipitation over the TP shows different spatial changes in the vegetation growing season, known as the time from May to September. The precipitation in the vegetation growing season and leaf area index(LAI) in the following month show a similar change pattern, indicating a"one-month lag"response of LAI to precipitation on the TP. Further analysis illustrates the influence of water vapor transport driven by the Asian summer monsoon. Water vapor derived from trans-equatorial air flows across the Indian Ocean and Arabian Sea is strengthened, leading to the increase of precipitation in the central and northern TP, where the trend of warming and wetting and the increase of vegetation tend to be more obvious. By contrast, as a result of the weakening trend of water vapor transport in the middle and low levels in southern TP, the precipitation decreases, and the LAI shows a downtrend, which inhibits the warming and wetting ecological environment in this area.