Global estimates of the energy transfer from the wind to the ocean, with emphasis on near‐inertial oscillations

Type Article
Date 2019-08
Language English
Author(s) Flexas M. Mar1, Thompson Andrew F.1, Torres Hector S.2, Klein Patrice2, Farrar J. Thomas3, Zhang Hong2, 4, Menemenlis Dimitris2
Affiliation(s) 1 : California Institute of Technology Pasadena 91125 CA, USa
2 : Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena California, USA
3 : Woods Hole Oceanographic Institution Woods Hole Massachussets, USA
4 : Joint Institute for Regional Earth System Science and EngineeringUniversity of California Los AngelesLos AngelesCalifornia, USA
Source Journal Of Geophysical Research-oceans (2169-9275) (American Geophysical Union (AGU)), 2019-08 , Vol. 124 , N. 8 , P. 5723-5746
DOI 10.1029/2018JC014453
WOS© Times Cited 9
Keyword(s) surface fluxes, inertial oscillations, wind power, kinetic energy budget, global ocean model, MITgcm
Abstract

Estimates of the kinetic energy transfer from the wind to the ocean are often limited by the spatial and temporal resolution of surface currents and surface winds. Here, we examine the wind work in a pair of global, very high‐resolution (1/48° and 1/24° ), MITgcm simulations in Latitude‐Longitude‐Cap configuration (LLC) that provide hourly output at spatial resolutions of a few kilometers and include tidal forcing. A cospectrum analysis of wind stress and ocean surface currents shows positive contribution at large scales (>300 km) and near‐inertial frequency, and negative contribution from mesoscales, tidal frequencies and internal gravity waves (IGWs). Larger surface kinetic energy fluxes are in the Kuroshio in winter at large scales (40 mW m−2) and mesoscales (‐30 mW m−2). The Kerguelen region is dominated by large scale (∼20 mW m−2), followed by inertial oscillations in summer (13 mW m−2) and mesoscale in winter (‐12 mW m−2). Kinetic energy fluxes from IGWs (‐0.1 to ‐9.9 mW m−2) are generally stronger in summer. Surface kinetic energy fluxes in the LLC simulations are 4.71 TW, which is 25%–85% higher than previous global estimates from coarser (1/6° –1/10° ) GCMs; this is likely due to improved representation of wind variability (6‐hourly, 0.14° , operational ECMWF). However, the low wind power input to the near‐inertial frequency band obtained with LLC (0.16 TW) compared to global slab models suggests that wind variability on time scales less than six hours and spatial scales less than 15 km are critical to better representing the wind power input in ocean circulation models.

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How to cite 

Flexas M. Mar, Thompson Andrew F., Torres Hector S., Klein Patrice, Farrar J. Thomas, Zhang Hong, Menemenlis Dimitris (2019). Global estimates of the energy transfer from the wind to the ocean, with emphasis on near‐inertial oscillations. Journal Of Geophysical Research-oceans, 124(8), 5723-5746. Publisher's official version : https://doi.org/10.1029/2018JC014453 , Open Access version : https://archimer.ifremer.fr/doc/00509/62058/