Grid-level source tracing and source variation of sand and dust storm affecting in Beijing

In this study, the authors developed a grid-level source apportionment model utilising GPU-accelerated computing, distinguishing it from previous studies where sand and dust storm source tracing was often restricted to broad geographical regions. Results show that Mongolia and Inner Mongolia contribute 47.3% and 39.7% of Beijing’s average dust concentration, respectively. During high-concentration events, Mongolia’s contribution surges to 71.9%. Critically, the grid-level source apportionment further revealed persistent hotspot grids, tightly concentrated along the China-Mongolia border corridor, including Dornogovi and Omnogovi (Mongolia) and the Sonid Left Banner and Siziwang Banner (Inner Mongolia).

Three transport pathways were identified as the primary routes for dust transport to Beijing. Notably, the pathway originating from the hotspot grids along the China-Mongolia border corridor has emerged as the dominant driver of the increasing frequency of severe SDS events. The recent increase in SDS activity along this corridor is primarily attributed to a higher frequency of gale days, exacerbated by fluctuations in vegetation coverage. These findings provide a solid scientific basis for targeted, cross-border desertification control to mitigate the impact of severe SDS on Beijing.