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Estimating the Four-Dimensional Structure of the Southern Ocean Using Satellite Altimetry
journal contribution
posted on 2023-05-17, 12:11 authored by Meijers, AJS, Nathaniel BindoffNathaniel Bindoff, Stephen RintoulA gravest empirical mode (GEM) projection of temperature and salinity fields over the circumpolar Southern Ocean is presented and is used in combination with satellite altimetry to produce gridded, full-depth, time-evolving temperature, salinity, and velocity fields. Optimal interpolation of historical hydrography, including Argo floats, is used to produce GEM projections of the circumpolar temperature and salinity fields. Parameterizing these fields by dynamic height allows the use of altimetric SSH values from 1992-2006 to create synoptic temperature and salinity fields at weekly intervals on a ⅓° grid at 36 depth levels. The satellite-derived temperature and salinity fields generally capture over 90% of the property variance below the thermocline, with RMS residuals of 1.16°C and 0.132 in salinity at the surface, decreasing to less than 0.45°C and 0.05 below 500 dbar. The combination of altimetry with the GEM fields allows the resolution of the subsurface structure of the filamentary fronts and eddy features. Velocity fields derived from the time-evolving temperature and salinity fields reproduce the Antarctic Circumpolar Current (ACC) velocity structure well, and are strongly correlated (r > 0.7) with in situ measurements from current meters and drifters, with RMS velocity residuals of 4.8-14.8 cm-1 in the Subantarctic Front.
History
Publication title
Journal of Atmospheric and Oceanic TechnologyVolume
28Issue
4Pagination
548-568ISSN
0739-0572Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Meteorological SocPlace of publication
45 Beacon St, Boston, USA, Ma, 02108-3693Rights statement
Copyright 2011 American Meteorological SocietyRepository Status
- Restricted