The water cycle over the Tibetan Plateau (TP) is vital to the regional and downstream climate and ecosystem. Clarifying the water cycle process and its interannual variability mechanism over the TP is important for the climate change adaptation activities. However, our current knowledge about the precipitation recycle ratio over the TP and its interannual variation remains inconclusive. Using the advanced reanalysis data ERA5 of the high resolution and a bulk model method, the water cycle over the TP is estimated in terms of the climatology and interannual variability. The climatic precipitation recycle ratio over the TP in summer is 23%. The reason for the contradictory conclusions between Curio et al. (2015, ) and other studies reviewed is analyzed and found to be related to the different definitions of the precipitation recycle ratio associated with the atmospheric water vapor mixture. The interannual variability of the precipitation recycle ratio over the TP in summer is significantly and negatively related with the Nino 3.4 index in the preceding winter. The precipitation recycle ratio decreases to 21.4% due to the more moisture inflow in the El Nino decaying summer. The change in the recycle ratio induced by the preceding El Nino events explains 60% of its interannual variability. The response of precipitation recycle ratio over the TP in summer to the preceding El Nino and La Nina events is asymmetric. Our study is conductive to reach the consensus on the climatic precipitation recycle ratio over the TP and advance our knowledge about its interannual variability mechanism.
Zhao, Y; Zhou, TJ
Interannual Variability of Precipitation Recycle Ratio Over the Tibetan Plateau
Journal Of Geophysical Research-Atmospheres