Strengthening impacts of spring sea surface temperature in the north tropical Atlantic on Indian Ocean dipole after the mid-1980s

Abstract It is well known that the Indian Ocean dipole (IOD) closely related to El Niño-Southern Oscillation (ENSO). In this study, it found spring–summer north tropical Atlantic (NTA) sea surface temperature (SST) anomalies can contribute development of IOD since mid-1980s as ENSO. After mid-1980s, an anticyclonic circulation over subtropical northeastern Pacific could be excited by cool NTA SST in spring and summer due a Gill-type Rossby-wave response. A low-level cyclonic appears west turn. The anomalous lower-level southwesterlies on southeastern flank reduce climatological wind speed, thus, warm appear extend central via wind-evaporation-SST (WES) feedback. As result, Walker Indo-Pacific region changed, with descending eastern ascending Pacific. branch generates southeasterly along coast off Sumatra lifts thermocline Ocean, which produces positive event autumn. Such cross-basin mechanism supported coupled model experiment perturbations NTA. contrast, although cold induce equatorial through interhemispheric meridional before responses are rather weak. addition, enhancement NTA-IOD relationship after suggested result from changes mean state under context global warming, confirmed two experiments different backgrounds.