Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming

By S. McGregor, A. Timmermann, M. Stuecker, M. England, Mark Merrifield, F. Jin, Y. Chikamoto. 2014

586 citations recorded by the source corpus.

The Pacific trade winds have strengthened since the late 1990s, and there has been related strengthening of the atmospheric Walker circulation. Although the impacts of these changes are becoming known, their cause has not been identified. This study, using observations and models, shows that warming of the Atlantic sea surface and corresponding displacement of atmospheric pressure centres are key drivers. An unprecedented strengthening of Pacific trade winds since the late 1990s (ref. 1) has caused widespread climate perturbations, including rapid sea-level rise in the western tropical Pacific2,3,4,5, strengthening of Indo-Pacific ocean currents6,7, and an increased uptake of heat in the equatorial Pacific thermocline1. The corresponding intensification of the atmospheric Walker circulation is also associated with sea surface cooling in the eastern Pacific, which has been identified as one of the contributors to the current pause in global surface warming1,8,9. In spite of recent progress in determining the climatic impacts of the Pacific trade wind acceleration, the cause of this pronounced trend in atmospheric circulation remains unknown. Here we analyse a series of climate model experiments along with observational data to show that the recent warming trend in Atlantic sea surface temperature and the corresponding trans-basin displacements of the main atmospheric pressure centres were key drivers of the observed Walker circulation intensification, eastern Pacific cooling, North American rainfall trends and western Pacific sea-level rise. Our study suggests that global surface warming has been partly offset by the Pacific climate response to enhanced Atlantic warming since the early 1990s.

Subfields: Atmospheric Science, Global and Planetary Change, Oceanography

View Paper: https://www.semanticscholar.org/paper/6e912d327cb0560f431b48c911c0a394eb973d6f

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Citations in the corpus

A Review of the Role of the Atlantic Meridional Overturning Circulation in Atlantic Multidecadal Variability and Associated Climate Impacts (2019, background): “The teleconnection is also consistents with simulated enhanced trade wind and surface cooling over the central and eastern equatorial Pacific forced by the specified observed surface warming over the tropical North Atlantic in recent decades (Li et al., 2016; McGregor et al., 2014).”
Seepage: Climate change denial and its effect on the scientific community (2015, background): “At a political level, the relative difficulty of ‘‘making something happen’’ over ‘‘leaving things as they are’’ was illustrated by McKay (2012), who showed that it takes 3.5 times as many lobbyists to make something happen in the U.S. Congress (positive lobbying) than to keep it from happening…”
Atlantic forcing of Pacific decadal variability (2016, background): “6a) clearly show an eastern Pacific cooling event with easterly wind anomalies in the central western Pacific, the Atlantic SSTs show a positive change everywhere.”
Combination Mode Dynamics of the Anomalous Northwest Pacific Anticyclone (2015, methodology): “…in certain regions, while either a thermodynamic SOM (Lau et al. 2005; Lau and Nath 2006; Lee et al. 2008; Lu et al. 2011; Lee et al. 2013; McGregor et al. 2014b) or a full dynamical ocean model (Kucharski et al. 2007; Kosaka et al. 2013; Kosaka and Xie 2013) is used in the remaining…”