banglin zhang

The latitudes of all Northern Hemisphere tropical cyclones (TCs) from the National Hurricane Center (NHC)/Joint Typhoon Warning Center (JTWC) best track data are used to investigate their poleward migration from 1970 to 2017. The annual means of the track latitudes are calculated for tropical storms, hurricanes/typhoons, and all storms over land and ocean, respectively. The analysis of the annual time series shows that TCs have shifted poleward more over land than over ocean, particularly for strong hurricanes and typhoons. For TC landfall, the analysis show hurricanes and typhoons made landfall gradually towards higher latitudes from 1970 to the early 2000s, and then the poleward trend levels off. The complexities of the poleward shifts are further compounded by the fact that the shifts are non-uniform from basin to basin. The predominant trend in the North Atlantic is the equatorward shift over ocean, while over the western Pacific it is a poleward shift over land. Poleward shifts of tropical cyclone positions may be attributable to the land-ocean contrast of surface temperature warming trends.