Western North Pacific Tropical cyclones act to suppress its adjacent Hadley circulation

The Hadley circulation (HC) is an important atmospheric circulation system connecting the tropics and subtropics, and variabilities of regional HC exhibit significant impacts on tropical cyclones (TC). However, the potential feedback of TC on the regional HC remains unclear. Here, we reveal that western North Pacific TC (WNPTC) activity exerts a significant 1-month lagged negative effect on the western Pacific HC intensity (WPHCI), and this relationship is independent of the influence of El Niño–Southern Oscillation (ENSO). We show that WNPTC activity can influence variations in environmental fields through modulating the variations of sea surface temperature over WP, thereby altering the thermal conditions and energy conversion, ultimately contributing to the weakening of the WPHC. The mechanism is further validated by sensitivity experiments. Our results demonstrate the significant effect of WNPTC activity on its adjacent meridional circulation, and illustrate the unignorable cumulative effect of extreme weather systems on the climate systems, which is especially important for that more frequent extreme events are projected under global warming.