Arid Zone Research ›› 2022, Vol. 39 ›› Issue (5): 1371-1384.doi: 10.13866/j.azr.2022.05.04

• Weather and Climate • Previous Articles     Next Articles

Spatiotemporal evolution of atmospheric water cycle factors in arid regions of Central Asia under climate change

GAO Jie1,2(),ZHAO Yong1(),YAO Junqiang2,Dilinuer TUOLIEWUBIEKE2,WANG Mengyuan3   

  1. 1. School of Atmospheric Science, Chengdu University of Information Technology, Chengdu 610225, Sichuan, China
    2. Institute of Desert Meteorology, China Meteorological Administration/Key Laboratory of Tree-Ring Physical and Chemical Research, China Meteorological Administration/Xinjiang Key Laboratory of Tree-Ring Ecology, Urumqi 830002, Xinjiang, China
    3. School of Atmospheric Science, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
  • Received:2022-02-17 Revised:2022-04-18 Online:2022-09-15 Published:2022-10-25
  • Contact: Yong ZHAO E-mail:gaojie997827@163.com;zhaoy608@cuit.edu.cn

Abstract:

The arid regions of Central Asia, which are “upstream” of China in terms of their influence on weather and climate, are characterized by a general shortage of water resources and the fragility of ecosystems. The atmospheric water cycle is the key link in the transformation of water resources and ecosystems in this region. In this study, we reassessed the temporal and spatial variation of water cycle elements, such as atmospheric water vapor content, water vapor budget, precipitation, and actual evaporation, in the arid region and subregions of Central Asia, from 1979 to 2018. The results of our analysis show clear spatial differences in the water cycle elements of Central Asia. Precipitation and actual evaporation are high in mountainous areas, such as Tianshan Mountains and Pamir and surrounding oasis areas, and low in the desert plain areas, whereas atmospheric water vapor content shows an opposite pattern. In terms of temporal changes, from 1979 to 2018, the water vapor content in Central Asia showed a weak decreasing trend, with obvious regional differences in the rate of change. Water vapor content in the surrounding areas of the Aral Sea decreased significantly, whereas in most of the areas of the Xinjiang and Tianshan Mountains, it increased significantly. Zonal transport is the main mode of water vapor transport in Central Asia, compared with the relatively weak meridional transport. Large differences were found in the water vapor budget over different regions; the water vapor transport tended to decrease in the western and northern boundaries and increased in the eastern and southern boundaries. Water vapor revenue and expenditure showed an increasing trend in northwestern Central Asia, southern Central Asia, the Pamir Plateau, and the Tianshan Mountains and a decreasing trend in northern Central Asia and most of Xinjiang. In contrast to the change in water vapor transport, the precipitation in Central Asia increased from 1979 to 2018, with an increase of 4.14 mm·(10a)-1 and a large interannual fluctuation. The significant increasing trend of precipitation is distributed in northern Central Asia and most of the Xinjiang and Tianshan Mountains, whereas there was a significant decreasing trend in northwestern and southern Central Asia. The actual evaporation in Central Asia showed a slight increasing trend, increasing significantly in the northern part of Central Asia, the Tianshan Mountains, and Pamir but decreasing significantly in the Caspian Sea area, Aral Sea, southern Central Asia, and southern Xinjiang. In terms of seasonal variation, the temporal and spatial distribution of seasonal and annual variations of water cycle elements was generally consistent. The results of our analysis contribute to a better understanding of the evolution and mechanism of the atmospheric water cycle in the arid regions of Central Asia.

Key words: Central Asian arid region, water cycle, water vapor content, precipitation, actual evaporation, water vapor budget