Open AccessEnergy Exchange between the Mesoscale Oceanic Eddies and Wind-Forced Near-Inertial Oscillations
Author(s) -
Zhao Jing,
Lixin Wu,
Xiaoyan Ma
Publication year - 2017
Publication title -
journal of physical oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 143
eISSN - 1520-0485
pISSN - 0022-3670
DOI - 10.1175/jpo-d-16-0214.1
Subject(s) - inertial wave , eddy , geology , mesoscale meteorology , geostrophic wind , mixed layer , wind stress , vorticity , ocean current , mechanics , climatology , meteorology , atmospheric sciences , turbulence , vortex , physics , mechanical wave , longitudinal wave , quantum mechanics , wave propagation
In this study, the energy exchange between mesoscale eddies and wind-forced near-inertial oscillations (NIOs) is theoretically analyzed using a slab mixed layer model modified by including the geostrophic flow. In the presence of strain, there is a permanent energy transfer from mesoscale eddies to NIOs forced by isotropic wind stress. The energy transfer efficiency, that is, the ratio of the energy transfer rate to the near-inertial wind work, is proportional to , where S 2 is the total strain variance,is the effective Coriolis frequency, and ζ is the relative vorticity. The theories derived from the modified slab mixed layer model are verified by the realistic numerical simulation obtained from a coupled regional climate model (CRCM) configured over the North Pacific. Pronounced energy transfer from mesoscale eddies to wind-forced NIOs is localized in the Kuroshio Extension region associated with both strong near-inertial wind work and strain variance. The energy transfer efficiency in anticyclonic eddies is about twice the value in cyclonic eddies in the Kuroshio Extension region because of the influence of ζ on f eff , which may contribute to shaping the dominance of cyclonic eddies than anticyclonic eddies in that region.