On the Coupling between the atmospheric circulation and the ocean wave field: an idealized case

Lionello P., P. Malguzzi, A. Buzzi

This work studies the two-way coupling between the atmospheric circulation and the ocean surface wave field, as it is described by the recent observations and theories on the dependence of the sea surface roughness on the ocean wave spectrum.
The effect of the coupling on the atmospheric variables and the ocean wave field is analysed by implementing both the atmospheric and the ocean wave models in a periodic channel and simulating a wide range of different situations. In a strong atmospheric cyclone, with respect to the one-way coupling, the two-way coupling attenuates the depth of the pressure minimum, significantly reduces the wave height and surface wind speed, while increases the momentum flux.
The heat and moisture fluxes are increased if they are computed using the same wave dependent roughness that is used for the momentum flux, while they are decreased if they are computed using Charnock relation.
The effects are proportionally larger for extreme storms because the time required for the deepening of the low pressure is much shorter than the time required by the windsea to reach a well developed state.