Spectral Analysis of Oceanic Surface Temperature Variance Drivers in a High-Resolution Atmosphere-Ocean Model

Ocean-atmosphere coupling affects the variability of Earth’s climate and weather on a wide range of temporal and spatial scales. However, the specific interactions that contribute to this coupling and the scales on which they act are not yet fully understood. The development of high-resolution coupled atmosphere-ocean models provides useful outputs to study weather and climate variability, particularly on shorter time and spatial scales. Here, a high-resolution configuration of the coupled GEOS-MITgcm atmosphere-ocean model is used to study heat fluxes in the atmospheric and oceanic boundary layers. The model comprises a cubed-sphere configuration of GEOS with 6.9 km horizontal grid spacing to a latitude-longitude-polar cap configuration of MITgcm with nominal grid spacing of 1/24^o. Hourly model outputs over western boundary current regions (Gulf Stream, Kuroshio, etc.) are analyzed over the course of one model year to capture the effects of ocean mesoscale eddies and high-velocity currents on the atmosphere-ocean boundary layer temperature variance budget. Spectra of the temperature variance budget terms are computed in order to identify the different scales at which atmosphere-ocean interactions modulate heat fluxes at the air-sea interface. Studies of these spectral terms in the ocean and atmosphere will provide insight into the drivers of variability in the atmosphere-ocean system at a range of spatial and temporal scales.