Modeling the surface heat flux response to long-lived SST anomalies in the North Atlantic

An atmospheric general circulation model (AGCM), a simplified atmospheric model (SAM) of surface heat flux, and various idealized analytic models have been used to investigate the atmospheric response over the North Atlantic to SST anomalies, including a general cooling associated with a weakened thermohaline circulation. Latent heating dominates the surface heat flux response, while sensible heating plays an important secondary role. All three kinds of atmospheric models exhibit nonrestorative behavior away from the anomaly peak that is primarily associated with the advection of cooled air eastward. This simple picture is complicated in the AGCM by the fact that the winds weaken over the SST anomaly, which helps to moderate the response. -from Authors