A Recent Reversal in the Poleward Shift of Western North Pacific Tropical Cyclones

Abstract

Recent studies have revealed a global, poleward migration trend of tropical cyclones (TCs) in terms of annual-averaged latitude of lifetime maximum intensity under the global warming. The TCs in the western North Pacific (WNP) make the largest contribution to this trend. One existing hypothesis is that there is a linkage between poleward migration of TCs and anthropogenic forcing. Here we introduce a new measurement, the lifetime-averaged latitude weighted by TC destructive potential, to detect the meridional migration of the WNP TCs, which is more reliable and meaningful as it considers not only past data uncertainty but also public concerns. Our results show that the trend of WNP TC migration reversed during the recent warming slowing-down period (after ~1999). Different from the existing hypothesis, it is the change of regional pattern of sea surface temperature that contributes greatly to the meridional migration of WNP TCs.