Why has the western Tibetan Plateau become wetter since the mid-1990s?

Jing Sun1, Kun Yang2, Weidong Guo3, Yan Wang4, Jie He1 and Hui Lu1, (1)Tsinghua University, Department of Earth System Science, Beijing, China, (2)Department of Earth System Science, Tsinghua University, Beijing, China, (3)Nanjing University, School of Atmospheric Sciences,Joint International Research Laboratory of Atmospheric and Earth System Sciences, Nanjing, China, (4)Tsinghua University, Beijing, China