Influences of variability of stable isotopes and composition of moisture sources on precipitation at multiple timescales in the Alpine regions of Central Asia

Congjian Sun; Xin Zhang; Shiyu Wang; Sijie Zhou

doi:10.1016/j.scitotenv.2023.162595

Influences of variability of stable isotopes and composition of moisture sources on precipitation at multiple timescales in the Alpine regions of Central Asia

Sci Total Environ. 2023 May 20:874:162595. doi: 10.1016/j.scitotenv.2023.162595. Epub 2023 Mar 4.

Authors

Congjian Sun¹, Xin Zhang², Shiyu Wang², Sijie Zhou²

Affiliations

¹ School of Geographical Sciences, Shanxi Normal University, Taiyuan 030031, China. Electronic address: suncongjian@sina.com.
² School of Geographical Sciences, Shanxi Normal University, Taiyuan 030031, China.

PMID: 36871715
DOI: 10.1016/j.scitotenv.2023.162595

Abstract

The accurate representation of variability of isotopic composition of modern precipitation based on long-term continuous monitoring is vital for interpreting hydrological and climatic processes. Based on measurements of δ²H and δ¹⁸O of 353 precipitation samples from five stations in the Alpine Mountains of Central Asia (ACA) during 2013-2015, the spatiotemporal variability of isotopic composition of precipitation and its controlling factors under multiple timescales were explored. Results showed that (1) the stable isotopes in precipitation at multiple timescales displayed an obviously inconsistent trend, especially in winter. (2) δ¹⁸O composition of precipitation (δ¹⁸O_p) under multiple timescales had a significant correlation with the variability of air temperature, except for in the case of the synoptic scale, while the correlation was weak between precipitation amount and variability in altitude. (3) The westerly wind had a stronger influence on the ACA, the southwest monsoon had an important influence on the transport of water vapor in the Kunlun Mountains region, and Arctic water vapor had a higher contribution to the region of the Tianshan Mountains. (5) The contribution rate of recycled vapor to precipitation ranged from 15.44 to 24.11 %, and the composition of moisture source of precipitation in arid inland areas of Northwestern China exhibited spatial heterogeneity. The results of this study improve our understanding of the regional water cycle and will enable the optimization of the allocation of regional water resources.

Keywords: Alpine regions of Central Asia; Isotope variability; Moisture source; Multiple timescales; Precipitation.