Validation and error analysis of OSCAR sea surface currents
Validation and error analysis of OSCAR sea surface currents
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DOI：
10.1175/jtech1971.1
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发表时间：
2007-04-01
影响因子：
2.2
通讯作者：
Mitchum, Gary T.
中科院分区：
文献类型：
--
作者：
Johnson, Eric S.;Bonjean, Fabrice;Mitchum, Gary T.
OSCAR卫星导出的海面流与来自系泊海流计、漂流器和船上海流剖面仪的现场数据的比较表明，OSCAR目前提供了纬向和纬向流的精确时间手段，在近赤道地区，（相关系数= 0.5 - 0.8）的纬向电流的周期短至40天和纬向波长短至8。在纬度高于10的纬向电流的相关性仍然可观，但OSCAR振幅减少不切实际。纬向流的变异性很难再现，与赤道上的纬向速度相比，振幅严重减小，相关性降低。OSCAR与漂流物速度的RMS差异与ECCO（估计海洋环流和气候）数据同化模式所经历的非常相似，但OSCAR通常提供更大的海洋相关信号，这提高了其估计信号与噪声的比率。即使使用目前可用的数据集，OSCAR保真度也存在一些适度改进的机会。
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.