An Assessment of Representation of Oceanic Mesoscale Eddy-Atmosphere Feedback in the Current Generation of General Circulation Models

Oceanic mesoscale eddies induce heat flux anomaly at the air-sea interface that in turn strongly damps eddy potential energy. So far it has remained unknown how well this oceanic mesoscale eddy-atmosphere (OMEA) feedback is represented in current generation of general circulation models. Here we evaluate uncertainties of OMEA feedback simulated in various models broadly used by the community. The intensity of OMEA feedback differs significantly among models in overall magnitude and spatial distribution. In eddy-rich regions such as Kuroshio Extension and Antarctic Circumpolar Current, the inter-model difference can reach 40%. Surface wind strength and marine atmospheric boundary layer (MABL) adjustment to eddy induced heat flux anomaly are two important factors accounting for inter-model difference of OMEA feedback. Models with stronger surface wind tend to have higher OMEA feedback. Moreover, neglecting MABL adjustment, ocean-alone model simulations overestimates OMEA feedback especially at mid and high latitudes by 20%-50%.