Validation and Error Analysis of OSCAR Sea Surface Currents

Eric S. Johnson, Fabrice Bonjean, Gary S. E. Lagerloef, John T. Gunn, Gary T. Mitchum

Research output: Contribution to journalArticlepeer-review

Abstract

Comparisons of OSCAR satellite-derived sea surface currents with in situ data from moored current meters, drifters, and shipboard current profilers indicate that OSCAR presently provides accurate time means of zonal and meridional currents, and in the near-equatorial region reasonably accurate time variability (correlation = 0.5–0.8) of zonal currents at periods as short as 40 days and meridional wavelengths as short as 8°. At latitudes higher than 10° the zonal current correlation remains respectable, but OSCAR amplitudes diminish unrealistically. Variability of meridional currents is poorly reproduced, with severely diminished amplitudes and reduced correlations relative to those for zonal velocity on the equator. OSCAR’s RMS differences from drifter velocities are very similar to those experienced by the ECCO (Estimating the Circulation and Climate of the Ocean) data-assimilating models, but OSCAR generally provides a larger ocean-correlated signal, which enhances its ratio of estimated signal over noise. Several opportunities exist for modest improvements in OSCAR fidelity even with presently available datasets.

Original languageAmerican English
JournalJournal of Atmospheric and Oceanic Technology
Volume24
DOIs
StatePublished - Jan 1 2007

Keywords

  • Currents
  • Satellite observations
  • In situ observations
  • Ship observations

Disciplines

  • Life Sciences

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