Woods Hole Oceanographic Institution

Steven R. Jayne

»Sc.D. Thesis
»Recirculation gyres in a beta-plane jet
»Forcing and sampling of ocean models
»Thermohaline circulation - sea ice feedback
»Recirculation forced by an unstable jet
»Tidal dissipation over rough topography
»Dynamics of ocean heat transport variability
»Deep ocean currents from GRACE
»Estimates of tidally-driven mixing
»Millennial climate variability
»Oceanic eddy heat transport
»Ocean heat content from GRACE
»Tidally-driven mixing in an ocean model
»Ocean bathymetry and Earth's climate
»Bathymetry from space
»Subtropical mode water during KESS
»North Atlantic Ocean circulation from GRACE
»Subtropical mode water in the Kuroshio Extension
»Tidal mixing during the Last Glacial Maximum
»Kuroshio northern recirculation gyre
»Bottom pressure in KESS and GRACE
»Ocean model metrics
»Abyssal mixing in CCSM
»Kuroshio Extension jet and transport
»The Morphology of Steve

S. R. Jayne , The circulation of the North Atlantic Ocean from altimetry and the GRACE geoid , Journal of Geophysical Research, 2006

We discuss the ocean circulation derived from the temporally averaged sea surface height, which is referenced to the recently released geoid from the Gravity Recovery and Climate Experiment (GRACE) mission (GRACE Gravity Model 02 (GGM02)). The creation of a precise, independent geoid allows for the calculation of the reference gravitational potential undulation surface, which is associated with the resting ocean surface height. This reference height is then removed from the temporally averaged sea surface height, leaving the dynamic ocean topography. At its most basic level the dynamic ocean topography can be related to the ocean’s surface circulation through geostrophy. This has previously been impracticable because of large uncertainties in previous estimates of the Earth’s geoid. Prior geoids included the temporally averaged sea surface from altimeters as a proxy for the geoid and therefore were unsuitable for calculations of the ocean’s circulation. Geoid undulations are calculated from the GRACE geoid and compared to those from the NASA Goddard Space Flight Center and National Imagery and Mapping Agency Joint Earth Geopotential Model (EGM96) geoid. Error estimates are made to assess the accuracy of the new geoid. The deep ocean pressure field is also estimated by combining the calculated dynamic ocean topography with hydrography. Finally, the derived circulation is compared to independent observations of the circulation from sea surface drifters and subsurface floats. It is shown that the GGM02 geoid is significantly more accurate for use in estimating the ocean’s circulation.

FILE » Jayne_2006.pdf

Dynamic Ocean Topography for the global ocean from GRACE as described in
Jayne, 2006, Circulation of the North Atlantic Ocean from altimetry and the
Gravity Recovery and Climate Experiment geoid, JGR-Oceans.

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