Impacts of Diverse El Niño Events on North Tropical Atlantic Warming in Their Decaying Springs

Abstract

AbstractPrevious studies have demonstrated that North Tropical Atlantic (NTA) warming can be modulated by El Niño events through atmospheric teleconnections. Considering the diversity of El Niño events, this study focuses on different responses of the NTA sea surface temperature (SST) to eastern Pacific (EP), central Pacific type I and type II (CP‐I and CP‐II) El Niño events in their decaying springs. In EP and CP‐II El Niño events, the pattern of NTA warming is well established, while the NTA SST fails to warm in CP‐I El Niño events. In EP and CP‐II El Niño events, anomalous cyclones can be excited in the subtropical Atlantic. Consequently, anomalous southwesterly winds in the NTA weaken the background northeasterly winds and suppress oceanic latent heat loss, leading to NTA warming. However, in CP‐I El Niño events, anomalous anticyclones are excited in the subtropical Atlantic and anomalous northeasterly winds in the NTA strengthen the background northeasterly winds, which facilitate oceanic latent heat loss and lead to NTA cooling. The inconsistent remote atmospheric responses of the NTA are attributed to the different patterns of warm and/or cold SST anomalies in the tropical Pacific in the decaying springs of different types of El Niño events. The physical mechanism linking the SSTs in the tropical Pacific and the NTA has been verified in a slab ocean model.