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Low‐mode internal tides and balanced dynamics disentanglement in altimetric observations: Synergy with surface density observations
Author(s) -
Ponte Aurélien L.,
Klein Patrice,
Dunphy Michael,
Le Gentil Sylvie
Publication year - 2017
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2016jc012214
Subject(s) - mesoscale meteorology , altimeter , internal tide , potential vorticity , ocean surface topography , vorticity , sea surface height , sea level , mode (computer interface) , geology , ocean dynamics , geodesy , inversion (geology) , climatology , ocean current , context (archaeology) , meteorology , internal wave , oceanography , physics , vortex , computer science , geomorphology , structural basin , operating system , paleontology
The performance of a tentative method that disentangles the contributions of a low‐mode internal tide on sea level from that of the balanced mesoscale eddies is examined using an idealized high resolution numerical simulation. This disentanglement is essential for proper estimation from sea level of the ocean circulation related to balanced motions. The method relies on an independent observation of the sea surface water density whose variations are 1/dominated by the balanced dynamics and 2/correlate with variations of potential vorticity at depth for the chosen regime of surface‐intensified turbulence. The surface density therefore leads via potential vorticity inversion to an estimate of the balanced contribution to sea level fluctuations. The difference between instantaneous sea level (presumably observed with altimetry) and the balanced estimate compares moderately well with the contribution from the low‐mode tide. Application to realistic configurations remains to be tested. These results aim at motivating further developments of reconstruction methods of the ocean dynamics based on potential vorticity dynamics arguments. In that context, they are particularly relevant for the upcoming wide‐swath high resolution altimetric missions (SWOT).