Characteristics and Mechanism of Water Vapour Resources in the Northern Slope of Kunlun Mountains

ABSTRACT

Atmospheric water resources in the northern slope of Kunlun Mountains (NKM) are a crucial limiting factor for regional economic development and ecological security. Consequently, it is urgent to accurately assess the atmospheric water vapour and potential mechanisms in NKM. Results show that MERRA‐2 data sets exhibit better performance in describing the evolution of water vapour transport and precipitation during 1980 to 2023 in the NKM relative to ERA5 and NCEP re‐analysis. Based on MERRA‐2, evapotranspiration (0.51 mm/decade) and precipitation (0.55 mm/decade) exhibited increasing trends during 1980 to 2023 in the NKM. Similarly, atmospheric water resources, consisting of water vapour content (99.65%) and cloud water (0.35%), also experience an increasing trend which is closely related to perturbed circulations of an anticyclone over the NKM. The upper branch of the anticyclone of southerly could bring abundant input water vapour to Kunlun Mountains, resulting in positive WVB (6.6 Gt/year). The mechanism is generalized as three key pathways of South Asian monsoon‐driven low‐level vapour transport, plateau thermal pumping and northward relay upper water vapour transport. Because of the ascending flow and water vapour convergence, the precipitation conversion rate (PCR) exhibits relatively higher values in the Kunlun Mountains than that in the Tarim Basin. Our findings could be conducive to understanding the characteristics of atmospheric water vapour resources in NKM and also provide scientific support for its utilization.