GEOMAR Helmholtz Centre for Ocean Research Kiel
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April 25, 2024: Ocean Circulation and Climate Dynamics Colloquium
Ingo Richter, JAMSTEC, Yokohama, Japan: "Which way Atlantic Niño? – How CMIP6 projections envision future variability in the equatorial Atlantic"
When? Thursday, 25 April 2024 at 2 pm
Where? Conference Room 5-1.213, Building 5, Wischofstr. 1-3 and
Zoom: https://geomar-de.zoom.us/j/84289388604?pwd=dGlpeTBUd1Nxem5Ec3dRYXh4NFpOUT09
Abstract:
Recent studies examining CMIP6 projections have indicated that the Atlantic Niño (also known as Atlantic zonal mode or AZM) will weaken under global warming. This has been associated with a weakened Bjerknes feedback that results from the stabilization of both the atmosphere and ocean. In the present study, we take a closer look at how these constraints influence the evolution of individual AZM events and their linkage to the tropical Pacific. Preliminary results suggest that, under increased greenhouse gas forcing, the influence of equatorial Atlantic SST anomalies on the atmospheric winds aloft becomes weaker and more confined to the lower troposphere. This is consistent with the weakened Bjerknes feedback that has been identified in previous studies. In addition, many models project a strengthening of the remote influence of equatorial Pacific SST anomalies on equatorial Atlantic surface winds. Thus, in those models, the local air-sea feedbacks in the equatorial Atlantic are replaced by remote control from the Pacific.
