Wind ringing of the ocean in presence of mesoscale eddies

Abstract

[1] Recent findings have highlighted the impact of high frequency (HF) winds on the inertial motions and the consequences on the large-scale oceanic circulation [Wunsch and Ferrari, 2004]. Within this context the present study focuses on the role of intermediate scales related to oceanic mesoscale eddies. Results show that a turbulent eddy field does not affect the impact of HF winds on the inertial motions. However the eddies efficiently and permanently concentrate the wind-forced inertial motions in small-scale anticyclonic structures. This leads to a spatially heterogeneous vertical mixing strongly related to the eddy field properties.

Vertical mixing and coherent anticyclones in the ocean: the role of stratification

“…Wunsch and Ferrari (2004) suggest that the wind driven near-inertial energy could sustain the small-scale mixing in the deep interior, needed to resupply the available potential energy removed by the overturning and mesoscale eddy generation. Theoretical considerations as well as modelling studies suggest that mesoscale flows could be responsible for transferring wind energy into the ocean interior through polarization of near inertial oscillations (Kunze, 1985;Klein et al, 2004;. Here we have shown that mesoscale anticyclones are "islands" of increased penetration of wind energy into the ocean interior, representing the maxima of available potential energy.…”

“…Recent works point to mesoscale vortices as responsible for transferring wind energy into the ocean interior through near inertial oscillations (Kunze, 1985;Klein et al, 2004;. Here, with a primitive-equation numerical model in an idealized set-up, we investigated the role of wind-forced anticyclones in the vertical mixing and the dependence of the (modeled) mesoscale ocean circulation on stratification, considering two different stratification profiles.…”

“…Their role on the horizontal motion has been studied extensively in the framework of 2d-barotropic, quasigeostrophic, and shallow water turbulence (e.g., McWilliams and Weiss, 1994;Provenzale, 1999;Bracco et al, 2004;Pasquero et al, 2004). The vertical structure of mesoscale vortices and the associated mixing, however, had long been viewed and parameterized in a simplified manner (Gent and McWilliams, 1995;Griffies, 2000) until recent findings have highlighted their role in transferring wind-forced near-inertial oscillations into the ocean interior (Kunze, 1985;Klein et al, 2004;. In this respect eddies constitute a different pathway by which inertial energy can reach the ocean interior and their contribution to vertical mixing may be fundamental in maintaining the meridional overturning circulation.…”

Submesoscale impacts on horizontal and vertical transport in the Gulf of Mexico

“…[] and later quantified by the frequency spectra in Figure b. Eddies are indeed capable of polarizing and transferring wind‐forced near‐inertial energy into the ocean interior [ Kunze , ; Klein et al ., ; Danioux et al ., ]. From a modeling prospective, such transfer is simulated only if the ocean model is forced with wind products containing energy at the frequencies to be excited [ Klein et al ., ; Cardona and Bracco , ] as in the present case (we use six hourly winds).…”

Estimates of tropical cyclone effects on the upper layer in the seas of Japan and Okhotsk

“…The TC outbreak to the seas of Japan and Okhotsk leads to a sharp increase in energy and mass exchange between the upper sea layer and surface air; as can be seen from the table, the thermal effect of TC in this case is as significant as the dynamic one. However, it should be noted that in the studies of TC effects on the Far East seas, the influence of the continent and of islands, as well as the time scale of the data under use, must be taken into account, because the results depend on them and this dependence can be significant [6]. …”