Reconstructing the ocean's interior from surface data

TitleReconstructing the ocean's interior from surface data
Publication TypeJournal Article
Year of Publication2013
AuthorsWang J.B, Flierl G.R, LaCasce J.H, McClean JL, Mahadevan A.
JournalJournal of Physical Oceanography
Date Published2013/08
Type of ArticleArticle
ISBN Number0022-3670
Accession NumberWOS:000323135400006
Keywordsbaroclinic modes; decomposition; eddies; energy; flow; geostrophic turbulence; Inverse methods; layer; north-atlantic; Ocean dynamics; Potential vorticity; precipitation; simulation; surface; Surface pressure; temperature

A new method is proposed for extrapolating subsurface velocity and density fields from sea surface density and sea surface height (SSH). In this, the surface density is linked to the subsurface fields via the surface quasigeostrophic (SQG) formalism, as proposed in several recent papers. The subsurface field is augmented by the addition of the barotropic and first baroclinic modes, whose amplitudes are determined by matching to the sea surface height (pressure), after subtracting the SQG contribution. An additional constraint is that the bottom pressure anomaly vanishes. The method is tested for three regions in the North Atlantic using data from a high-resolution numerical simulation. The decomposition yields strikingly realistic subsurface fields. It is particularly successful in energetic regions like the Gulf Stream extension and at high latitudes where the mixed layer is deep, but it also works in less energetic eastern subtropics. The demonstration highlights the possibility of reconstructing three-dimensional oceanic flows using a combination of satellite fields, for example, sea surface temperature (SST) and SSH, and sparse (or climatological) estimates of the regional depth-resolved density. The method could be further elaborated to integrate additional subsurface information, such as mooring measurements.

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