Drying Effect of Landfalling Tropical Cyclones

Abstract The high precipitation efficiency of tropical cyclones (TCs) is theorized to dehydrate the atmosphere, a process with important climate implications that has yet to be confirmed by direct observational evidence. Using satellite and reanalysis data, this study statistically examines the drying effect of landfalling TCs. Results indicate a local atmospheric memory of landfalling TCs, lasting for approximately 15 days. After TC passage, the local atmosphere is characterized by a decrease in atmospheric moisture, particularly at the 600 hPa level in the mid‐troposphere. Atmospheric drying results from local moisture removal by TC precipitation and the anomalous westerly advection of a drier atmosphere. As a result, the local rainfall and rain probability are decreased by 15% and 18%, respectively, 10–15 days after the TC passage, compared to climatology. This provides new evidence of TCs' persistent impact on the climate system and their key role in the regional water cycle.