Presenter: Avik Mondal (University of Michigan)

Description:
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 ocean. 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 vertical heat flux in the ocean mixed layer and thermocline. Spectra of the vertical heat flux components are computed at the atmosphere-ocean interface in order to understand the space and time scales of atmospheric heat input into the ocean. In the ocean bulk, spectra of the vertical heat flux at different levels are computed to compare the space and time scales over which advection and diffusion act on the overall vertical heat flux.