Impacts of climate trends on the heavy precipitation event associated with Typhoon Doksuri in Northern China

The remnant inland circulation of Typhoon Doksuri induced catastrophic heavy precipitation in July 2023 in the Beijing-Tianjin-Hebei area of China. The role of climate trends in this event is investigated using the pseudo-global warming approach. The control experiment driven by the ERA5 reanalysis captures the intensity and spatial distribution of the heavy precipitation reasonably well. The effects of climate trends are investigated by removing climate trends in various variables from the boundary and initial conditions of the sensitivity experiments. The warming trend of sea surface temperature is found to enhance extreme precipitation intensity, while the specific humidity trend, which is positive over the ocean but negative in some inland regions, has negligible impacts on inland extreme precipitation. The impacts of atmospheric dynamic trends are found to be predominant, which alter the track of the remnant circulation, reduce precipitation intensity, and substantially change the spatial distribution of precipitation. This study highlights the importance of considering atmospheric dynamic trends when assessing the impacts of climate trends on typhoon remnant circulations over land, which may lead to extreme precipitation in regions that have rarely experienced such extremes before.