资源环境科技发展态势分析平台

Determining the sources of moisture for the devastating precipitation event over Henan in July 2021 helps understand the mechanisms of such extreme precipitation events. In this study, the moisture sources and transport trajectories for the event are investigated using a Lagrangian approach. Moisture is transported to Henan along three routes that are driven by the western Pacific subtropical high (WPSH), WPSH and the tropical cyclone In-Fa, as well as WPSH and the tropical cyclone Cempaka, respectively. The WPSH-In-Fa-driven air parcels have the highest moistening and precipitating efficiency among the 1704three routes. Overall, southern China contributes the most to moisture sources (38.1%), followed by the western North Pacific (30.0%). The results indicate that the terrestrial and oceanic moisture over southern China-western North Pacific are both crucial for the extreme precipitation event over Henan.