A two-decade time series of eddy-resolving dynamic ocean topography (iDOT)
A two-decade time series of eddy-resolving dynamic ocean topography (iDOT)
复制标题
涡旋解析动态海洋地形 (iDOT) 的两个十年时间序列
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
C. Schwatke
中科院分区：
文献类型：
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作者：
W. Bosch;R. Savcenko;D. Dettmering;C. Schwatke
GOCE导出的重力场的显著改进允许现在通过从海面高度（SSHS）减去大地水准面来推断动态海洋地形（DOT）。虽然大地水准面，从带限重力场模型，是相对平滑的，可以计算无处不在，SSH观测沿着高度计地面轨迹，并表现出高频率的变化。因此，大地水准面和SSH将被一致地过滤。我们应用“剖面方法”沿沿着个别地面轨迹执行这样的滤波和减法。这样，可以为任何高度计卫星的所有地面轨迹生成瞬时DOT轮廓（iDOT）。我们应用这种方法仔细交叉校准多任务测高自1993年以来。随后，所有iDOT配置文件的组合集网格与10天的采样周期，以构建一个DOT时间序列跨越期间1993年至今。GOCE重力场的高质量允许将滤波器长度减少到大约70 km，这样DOT时间序列可以分辨中尺度涡旋。对于西部边界流，动画显示了涡旋和相关地转速度场的演变，这反过来又可以推断涡旋动力学。
The significant improvements of GOCE derived gravity fields allows now to infer the dynamic ocean topography (DOT) by subtracting the geoid from sea surface heights (SSHs). While the geoid, derived from a band-limited gravity field model, is relative smooth and can be computed everywhere, the SSHs are observed along the altimeter ground tracks and exhibit high frequency variations. Thus, geoid and SSHs are to be consistently filtered. We apply a “profile method” performing such a filtering and subtraction along individual ground tracks. This way instantaneous DOT profiles (iDOT) can be generated for all ground tracks of any altimeter satellite. We apply this method to carefully cross calibrated multi-mission altimetry available since 1993. Subsequently, the combined set of all iDOT profiles is gridded with 10-day sampling periods to construct a DOT time series spanning the period 1993 up to now. The high quality of GOCE gravity fields allows to reduce the filter length down to some 70 km such that the DOT time series resolves meso-scale Eddies. For the western boundary currents animations show the evolution of Eddies and of the associated geostrophic velocity field which in turn allows to infer the Eddy kinetic