Arid Zone Research ›› 2022, Vol. 39 ›› Issue (5): 1345-1359.doi: 10.13866/j.azr.2022.05.02

• Weather and Climate • Previous Articles     Next Articles

Characteristics of the difference in air water resources between the north and south slopes of the Qilian Mountains in the summer

BA Li1,2(),YIN Xianzhi1(),PANG Zhaoyun1,CHENG Peng3,LIU Weicheng4,WANG Yanfeng1   

  1. 1. Gansu Weather Modification Office, Lanzhou 730020, Gansu, China
    2. Key Laboratory for Cloud Physics of China Meteorological Administration, Beijing 100081, China
    3. Meteorological Service Center of Gansu Province, Lanzhou 730020, Gansu, China
    4. Lanzhou Central Meteorological Observatory, Lanzhou 730020, Gansu, China
  • Received:2021-12-14 Revised:2022-06-13 Online:2022-09-15 Published:2022-10-25
  • Contact: Xianzhi YIN E-mail:bllnuist@hotmail.com;lbz319@aliyun.com

Abstract:

The different characteristics of air cloud water resources between the southern and northern slopes of the Qilian Mountains in the summer were studied using ERA5 reanalysis data with a high temporal and spatial resolution provided by ECMWF to provide a reference for the rational development of air water resources in this area. The water vapor condensation efficiency and water condensate precipitation efficiency were estimated. The results show the following: (1) the water vapor content on the southern slope is slightly lower compared to the northern slope in the summer on average, and the cloud water path on the southern slope is higher compared to the northern slope. The cloud liquid water content on the southern slope was rich below 500 hPa. The water vapor content and cloud liquid water content showed an upward trend in recent years, and the growth rate of the southern slope was higher compared to the northern slope. The cloud ice water content showed a decreasing trend, and the decreasing rate was higher in the northern slope compared to the southern slope. (2) The convergence and upflow of the low-level water vapor field caused by atmospheric circulation and topography play a key role in the distribution of cloud water resources in the Qilian Mountains. (3) The distribution of cloud water on the northern slope was more abundant compared to the southern slope with a west-northwest airflow pattern, and low water-bearing clouds were mainly present under different precipitation circulation patterns. Cloud thickness is deeper in southwest airflow patterns, and there is little difference between cloud water in the northern and southern slopes. (4) In the Qilian Mountains, especially on the southern slope, the cloud water resources in the air were relatively rich, and most of the water condensation fails to precipitate. Thus, there is a certain space for the development of air water resources. The uneven and variable distribution of cloud water resources requires a more targeted selection of operational areas and means in the development process.

Key words: Qilian Mountains, north-south difference, cloud water