A comparison of GOCE and drifter-based estimates of the North Atlantic steady-state surface circulation

Bingham, R. J., Haines, K. ORCID: https://orcid.org/0000-0003-2768-2374 and Lea, D. (2015) A comparison of GOCE and drifter-based estimates of the North Atlantic steady-state surface circulation. International Journal of Applied Earth Observation and Geoinformation, 35 (A). pp. 140-150. ISSN 0303-2434 doi: 10.1016/j.jag.2014.03.012

Abstract/Summary

Over the last decade, due to the Gravity Recovery And Climate Experiment (GRACE) mission and, more recently, the Gravity and steady state Ocean Circulation Explorer (GOCE) mission, our ability to measure the ocean’s mean dynamic topography (MDT) from space has improved dramatically. Here we use GOCE to measure surface current speeds in the North Atlantic and compare our results with a range of independent estimates that use drifter data to improve small scales. We find that, with filtering, GOCE can recover 70% of the Gulf Steam strength relative to the best drifter-based estimates. In the subpolar gyre the boundary currents obtained from GOCE are close to the drifter-based estimates. Crucial to this result is careful filtering which is required to remove small-scale errors, or noise, in the computed surface. We show that our heuristic noise metric, used to determine the degree of filtering, compares well with the quadratic sum of mean sea surface and formal geoid errors obtained from the error variance–covariance matrix associated with the GOCE gravity model. At a resolution of 100 km the North Atlantic mean GOCE MDT error before filtering is 5 cm with almost all of this coming from the GOCE gravity model.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/36481
Identification Number/DOI	10.1016/j.jag.2014.03.012
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Elsevier
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