North Atlantic as a Trigger for Pacific‐Wide Decadal Climate Change

Abstract

AbstractThe Interdecadal Pacific Oscillation (IPO) features a basin‐scale horseshoe‐like sea surface temperature (SST) anomaly pattern. Its cold‐phase shift around 1999, implicated as a driver for the early‐2000s global warming slowdown, has been potentially linked to the Atlantic warming during the positive‐phase Atlantic Multidecadal Variability (AMV). However, the key mechanism for the trans‐basin Atlantic‐Pacific teleconnection remains debatable. Here, we show that an AMV‐SST cooling can initiate a pan‐Pacific response. The North Atlantic cooling induces westerly wind anomalies over the central‐western equatorial Pacific as Kelvin‐wave responses and easterly wind anomalies over the far‐eastern equatorial Pacific as Rossby‐wave responses. Additionally, anomalous lows are generated over the extratropical North and South Pacific through the midlatitude Rossby wave propagation. The tropical and midlatitude teleconnections act together to develop into a warm‐phase IPO‐like pattern through the wind‐induced latent heat. Our results suggest a potential of advancing the predictability of IPO through a skillful simulation of AMV.