Poleward migration of western North Pacific tropical cyclones related to changes in cyclone seasonality

Xiangbo Feng; Nicholas P Klingaman; Kevin I Hodges

doi:10.1038/s41467-021-26369-7

Poleward migration of western North Pacific tropical cyclones related to changes in cyclone seasonality

Nat Commun. 2021 Oct 27;12(1):6210. doi: 10.1038/s41467-021-26369-7.

Authors

Xiangbo Feng¹, Nicholas P Klingaman², Kevin I Hodges²

Affiliations

¹ National Centre for Atmospheric Science and Department of Meteorology, University of Reading, Reading, UK. xiangbo.feng@reading.ac.uk.
² National Centre for Atmospheric Science and Department of Meteorology, University of Reading, Reading, UK.

Abstract

The average location of observed western North Pacific (WNP) tropical cyclones (TCs) has shifted north over the last several decades, but the cause remains not fully understood. Here we show that, for the annual average, the observed northward migration of WNP TCs is related to changes in TC seasonality, not to a northward migration in all seasons. Normally, peak-season (July-September) TCs form and travel further north than late-season (October-December) TCs. In recent decades, related to less frequent late-season TCs, seasonally higher-latitude TCs contribute relatively more to the annual-average location and seasonally lower-latitude TCs contribute less. We show that the change in TC seasonality is related to the different responses of late-season and peak-season TC occurrence to a stronger Pacific Walker Circulation. Our findings provide a perspective on long-term trends in TC activity, by decomposing the annual-average statistics into seasonal components, which could respond differently to anthropogenic forcing.

Publication types

Research Support, Non-U.S. Gov't