Weakening anomalies of East Asian Summer Precipitation Influenced by the Tibetan Plateau Warming Amplification

Abstract. The present study documents the on East Asian precipitation in summer influenced by elevation-dependent temperature change over the Tibetan Plateau (TP). The temperature of the TP and its surrounding areas decreases with altitude by 0.43–0.45 °C/100 meters, which is lower than the 0.6 °C/−100 meters in the troposphere. The magnitude of the trend of temperature increase with elevation and the amplification of warming over the TP comprise an important feature of the temperature change. TP warming is consistently the important contributor to the variation of East Asian precipitation in summer from 1979 to 2016, but their relationship weakens as the warming over the TP amplifies. The southern flood–northern drought pattern is weak compared with when the TP warming trend has been removed. Warming amplification of the TP may weaken the atmospheric circulation anomaly pattern. The rate of anticyclonic circulation strengthening has slowed in the upper and lower levels over Mongolia in East Asia, which leads to the northern drought feature weaken. Meanwhile striking cyclonic circulation anomalies are reduced in the southeastern part of China, the northern part of the South China Sea, and the northwestern Pacific. The atmospheric response to TP warming might be related to two distinct Rossby wave trains. After TP warming amplifying, one in the extratropics that moves along the upper-level westerly jetstream and the other in the tropics that moves along the low-level monsoon westerly have weakened. The downdrafts prevailed in the Northern Asia receded, which is conducive to precipitation in the area. Updrafts prevailed in the Southeast Asia is deteriorating, which is not advantageous to precipitation.