While the Atlantic Meridional Overturning Circulation (AMOC) has had a long-standing role in global climate, indirect proxies of ocean circulation are required to make inferences about past trends in order to understand changes in AMOC’s strength from before there were instruments to measure it. Several previous analyses have used sea surface temperature indices to interpret 20th century AMOC trends. However, researchers funded in part by CPO’s Climate Variability & Predictability (CVP) program, have used two climate model ensembles to assess the relationship between AMOC and sea surface temperature at century timescales. They found that those relationships are strongly dependent on time period and climate forcing, suggesting that sea surface temperature indices are poor predictors of 100-year variations in AMOC strength. The study, published in Geophysical Research Letters, does not draw any conclusions about using surface-temperature-based indices to capture AMOC variability on multidecadal timescales.
Are Sea Surface Temperature Indices the Right Proxy for 100-year Trends in AMOC?
