Western tropical Pacific multidecadal variability forced by the Atlantic multidecadal oscillation

Abstract

Observational analysis suggests that the western tropical Pacific (WTP) sea surface temperature (SST) shows predominant variability over multidecadal time scales, which is unlikely to be explained by the Interdecadal Pacific Oscillation. Here we show that this variability is largely explained by the remote Atlantic multidecadal oscillation (AMO). A suite of Atlantic Pacemaker experiments successfully reproduces the WTP multidecadal variability and the AMO–WTP SST connection. The AMO warm SST anomaly generates an atmospheric teleconnection to the North Pacific, which weakens the Aleutian low and subtropical North Pacific westerlies. The wind changes induce a subtropical North Pacific SST warming through wind–evaporation–SST effect, and in response to this warming, the surface winds converge towards the subtropical North Pacific from the tropics, leading to anomalous cyclonic circulation and low pressure over the WTP region. The warm SST anomaly further develops due to the SST–sea level pressure–cloud–longwave radiation positive feedback. Our findings suggest that the Atlantic Ocean acts as a key pacemaker for the western Pacific decadal climate variability.

A Review of the Role of the Atlantic Meridional Overturning Circulation in Atlantic Multidecadal Variability and Associated Climate Impacts

“…The center of action of this multidecadal climate mode is over the Atlantic and resembles AMV. A positive AMV phase is teleconnected with warming over the western tropical Pacific and North Pacific through both extratropical and tropical pathways, as also simulated in an AGCM‐AMV experiment (Sun et al, ). This multidecadal climate mode is closely linked to multidecadal AMOC variability and associated tropical AMOC fingerprint (i.e., the anticorrelation between multidecadal tropical North Atlantic surface and subsurface temperature anomalies) in the CGCM, suggesting an essential role of the AMOC as a pacemaker for the interbasin teleconnected multidecadal climate mode (Barcikowska et al, ).…”

Widespread Reemergence of Sea Surface Temperature Anomalies in the Global Oceans, Including Tropical Regions Forced by Reemerging Winds

“…Further, the winter‐to‐winter recurrence of SSTA is strongly influenced by the interannual and interdecadal variability of SSTA (Möller et al, ; Zhao & Li, ). A recent study (Sun et al, ) has found a prominent connection for multidecadal variability of wind and SST in the western tropical Pacific forced by the Atlantic Multidecadal Oscillation. Therefore, a recurrence of wind‐stress and heat flux anomalies in the tropics (e.g., western tropical Pacific) could be modulated by the decadal climate variability.…”

Recent Acceleration of Arabian Sea Warming Induced by the Atlantic‐Western Pacific Trans‐basin Multidecadal Variability

“…In fact, a recent study has suggested that there is a significant footprint of the AMO in the WP SST, producing an SST pattern of Atlantic-Western Pacific trans-basin multidecadal variability (AWPMV in short), which is formed through several processes including an atmospheric teleconnection from the North Atlantic to the North Pacific and feedbacks between the atmosphere and ocean in the subtropical and tropical Pacific (Sun et al, 2017). The AWPMV has also been identified as the leading mode of global internal decadal SST variability (Chen & Tung, 2018).…”