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Free keywords:
WAVE-NUMBER SPECTRUM; NORTH-ATLANTIC; MESOSCALE VARIABILITY; SPATIAL SCALES; KINETIC-ENERGY; ALTIMETER; CIRCULATION
Abstract:
Frequency and along-track wave number spectra of zonal (u) and meridional (v) geostrophic surface velocity anomalies, retrieved from the Jason-1-TOPEX/Poseidon (JTP) tandem mission, are presented as global, basin, latitudinal, and regional averages. Over the entire extratropical ocean, frequency spectra show slightly higher energy levels for the v component in the frequency range below 100 days relative to the u component, a lower energy for periods longer than 180 days. Furthermore, quasi-universal frequency slopes of close to f(-2) are found for the high-frequency part of all extratropical spectra representing regions with various different eddy energy levels. Differences in wave number spectra between u and v velocity components both computed along the satellite track result primarily from the sampling of the flow field on the JTP-track with a meridionally changing track orientation. Taking this into account, nearly similar spectral shapes are found for the wave number spectra of both velocity components over extratropical regions.
