Characteristics and sources of chemical composition in precipitation on the Loess Plateau of China

Knowing the sources of precipitation chemical composition is essential to understand the biogeochemical cycle and control air pollution. Despite this issue has been directly investigated with precipitation ion contents, the effects of water vapor transport have not been fully considered. Taking the Loess Plateau of China (LPC) as an example study area, this study established nine precipitation monitoring sites considering the variability in topography and rainfall amounts, and collected 435 precipitation samples during 2020-2022 to measure the chemical composition. The correlation analysis, positive matrix factorization model and backward trajectory model were combined to analyze the characteristics, sources and vapor transport effects of precipitation chemical composition. Seasonally, except for NH