Regional Hadley Circulation Adjustments Associated With Eastern‐Pacific and Central‐Pacific ENSO

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Abstract The El Niño‐Southern Oscillation (ENSO) exhibits pronounced spatial diversity between its eastern Pacific (EP) and central Pacific expressions, with distinct impacts on the global atmospheric circulation, including the Hadley circulation (HC). However, the traditional zonal‐mean perspective of the HC masks the longitudinal structure of the circulation responses to different ENSO types, thereby concealing basin‐dependent overturning contrasts and their implications for HC‐subtropical jet interactions. In this study, we show that different ENSO types induce distinct three‐dimensional adjustments of the HC. During CP‐type events, Pacific HC cells exhibit a broader meridional extent with centers shifted farther west, resulting in a stronger coupling with the subtropical jet, whereas EP‐type events are characterized by a more zonally broadened HC confined near the equator. These contrasts extend beyond the Pacific basin, with Atlantic HC anomalies during CP‐type events also displaced farther westward than those associated with EP‐type events. The differing HC responses are closely linked to the distinct spatial patterns and seasonal evolution of sea surface temperature and precipitation anomalies associated with different ENSO types. Together, these findings enhance our understanding of ENSO diversity and its climatic impacts, particularly in the context of the projected increase in CP‐type events under global warming.

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