The Influence of the Tibetan Plateau Monsoon on Summer Precipitation in Central Asia

Shaobo Zhang,Lixia Meng,Anning Huang,Xianyu Yang,Yong Zhao

doi:10.3389/feart.2022.771104

Abstract

As a unique climate phenomenon induced by the Tibetan Plateau (TP) heat flux, the TP monsoon is closely connected with the global climate, especially pertaining to the TP. However, the current research focuses more on the influence of the TP monsoon on the TP and eastern China, but not including Central Asia. This paper analyzed the relationship between the TP monsoon index and Central Asia summer precipitation by JRA55 reanalysis data and Global Precipitation Climatology Centre (GPCC) monthly precipitation. The results showed a significant positive relationship between the TP monsoon index and summer precipitation in Central Asia. When the TP monsoon was strong, there was cold advection in the upper troposphere over Central Asia, and the resulting thermal wind caused a cyclonic circulation anomaly in the mid-upper troposphere over Central Asia. This in turn led to a cyclonic circulation anomaly to water vapor transport in the lower troposphere. The abnormal upward movement also caused more precipitation in this area, which explains the positive correlation between the TP monsoon and the precipitation in Central Asia. Based on this physical mechanism, the temperature of the mid-upper troposphere over Central Asia was closely related to the TP monsoon, and it was a key factor that affected summer precipitation changes in Central Asia.

Highlights

The arid and semiarid regions in Central Asia, including Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, are sensitive and vulnerable to climate variations (Hu et al, 2014)
What is the relationship between the precipitation in Central Asia and the Tibetan Plateau (TP) monsoon? Based on this consideration, this paper studied the relationship between the TP monsoon and precipitation in Central Asia and discussed the role of the midupper tropospheric temperature in the relationship
The TP monsoon was closely related to the precipitation in Central Asia, and there was a significant positive correlation

Summary

Introduction

The arid and semiarid regions in Central Asia, including Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, are sensitive and vulnerable to climate variations (Hu et al, 2014). Taking 100°E as the boundary, the arid area of central Asia is controlled by westerly circulation; this area was named the “westerly mode” (Huang et al, 2013). Huang et al (2015) found that the “westerly mode” of precipitation changes under the modern climate background was most prominent feature on the interdecadal scale in summer. Xu et al (2015) found that the average increasing rate in annual precipitation was 3.9 mm/10 a in the arid lands of Central Asia, and there were significant increasing trends in precipitation in Kazakhstan, Kyrgyzstan, and Tajikistan. Yao et al (2021) found that all extreme precipitation-related indices except for consecutive dry days experienced an increasing trend during 1936–2005.

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