Impacts of central Pacific and eastern Pacific El Niños on tropical cyclone tracks over the western North Pacific

Abstract

[1] This study examines the different impacts of two types of El Niños, the eastern Pacific El Niño (EP-EN) and the central Pacific El Niño (CP-EN), on tropical cyclone (TC) tracks over the western North Pacific (WNP) based on observational data. Whereas TC tracks between CP-EN and EP-EN show a small difference in boreal summer (JJA), they do exhibit a great difference in boreal autumn (SON), that is, TCs recurve northward at a further westward location near the coastline of East Asia during CP-EN. As a consequence, more TCs make landfall to Taiwan and South China during CP-EN. A further observational analysis indicates that the westward shift of the subtropical high and associated steering flow during CP-EN is a key factor that causes the difference in the TC tracks in autumn. Numerical experiments further suggest that the difference of local SST in the WNP between CP-EN and EP-EN accounts for the distinctive differences in the local Hadley circulation, the subtropical high and the TC steering flow.