Identifying the roles of the ocean and atmosphere in creating a rapid equatorial response to a Southern Ocean anomaly

Abstract

Recent research has identified a rapid ocean response mechanism to salinity anomalies in the Southern Ocean using an idealised ocean model. Here we examine the relative importance of the ocean and atmosphere in creating an equatorial response to a Southern Ocean anomaly. Using a coupled climate model with realistic bottom topography and land relief, two rapid teleconnections are produced from a high latitude anomaly. An equatorial ocean response can be seen after 30 days. The mechanism producing this response is shown to rely on barotropic and baroclinic oceanic wave propagation. A second, atmospheric, response is seen in the Northern Hemisphere (NH) high latitudes, driven by atmospheric Rossby waves. The ocean quickly responds to the atmospheric signal above it, resulting in sea surface temperature anomalies at NH high latitudes.