Spatial structural changes of summer storms over the Tibetan Plateau during 2001-2020 based on GPM IMERG data

The Tibetan Plateau (TP), known as the "Asian Water Tower," plays a crucial role in regional water resources, with summer storms contributing significantly to annual precipitation. However, the spatial structural changes of these storms remain understudied. This study analyzed satellite-retrieved precipitation data from 2001 to 2020 to investigate the changes in the spatial structure of summer storms over the TP and their underlying mechanisms. Results showed distinct regional differences: in the monsoon-dominated zone, reduced precipitation particularly at the storm center, led to a "dulling" of storm structures. In contrast, in the westerly-dominated and transition zones, a greater increase in precipitation was found at the center compared to other regions of storms, especially for extreme storms, resulted in a "sharpening" of storm structures. Ignoring the changes of spatial structural changes may overestimate the changes of storm-induced precipitation. Further analysis linked these changes to dynamic environmental factors, particularly stronger variations in vertical velocity near the storm center, driven by large-scale circulation changes around the TP.