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Universal structure of mesoscale eddies in the ocean
Author(s) -
Zhang Zhengguang,
Zhang Yu,
Wang Wei,
Huang Rui Xin
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50736
Subject(s) - argo , mesoscale meteorology , eddy , geology , altimeter , amplitude , sea surface height , ocean dynamics , satellite altimetry , water mass , buoyancy , geodesy , physics , geophysics , climatology , meteorology , mechanics , ocean current , oceanography , optics , turbulence
Mesoscale eddies dominate oceanic kinetic energy at sub‐initial frequencies. Their three‐dimensional structure has, however, remained obscure, hindering better understanding of eddy dynamics. Here by applying the composite analysis of satellite altimetry and Argo float data to the globe, we show that despite remarkable regional differences in amplitude, extent and polarity, etc., mesoscale eddies have a universal structure in normalized stretched coordinates. Horizontally, the associated pressure anomaly is well described by a function of the normalized radial distance from the eddy center R(r n )=(1−r n 2 /2)· exp(−r n 2 /2), whereas vertically it is sinusoidal in a stretched coordinatez s = ∫ 0 z ( N / f ) dz , where N and f are the buoyancy frequency and the Coriolis parameter.