An observed 20-year time series of Agulhas leakage
An observed 20-year time series of Agulhas leakage
复制标题
观察到的厄加勒斯泄漏 20 年时间序列
DOI：
10.5194/os-10-601-2014
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发表时间：
2014
期刊：
影响因子：
3.2
通讯作者：
W. D. Ruijter
中科院分区：
文献类型：
--
作者：
D. Bars;Jonathan V. Durgadoo;H. Dijkstra;A. Biastoch;W. D. Ruijter
我们提供了一个时间序列的Agulhas泄漏异常在过去20年的卫星测高。迄今为止，印度洋-大西洋交换的年际变化一直是研究Agulhas泄漏的动力学和大尺度影响的主要障碍。我们计算了厄古拉斯电流和厄古拉斯返回电流之间的输运差异，这使得我们能够推断厄古拉斯泄漏。主要的困难是将厄古拉斯回流与非洲南部亚热带“超级环流”的南翼分开。为此，开发了一种使用绝对动态地形数据的算法。该算法适用于一个国家的最先进的海洋模型。与拉格朗日方法测量泄漏的比较使我们能够验证新方法。一个重要的结果是，它是可能的测量在这个模型中使用的速度场沿着一个部分，既跨越了Agulhas电流和Agulhas回流泄漏。在模型中，一个很好的相关性之间的测量泄漏使用的全深度速度和只使用表面地转速度。这使我们能够扩展的方法，沿轨道绝对动态地形卫星。结果表明，平均动态地形的准确性不允许我们确定的平均泄漏，但泄漏异常可以准确计算。
We provide a time series of Agulhas leakage anomalies over the last 20-years from satellite altimetry. Until now, measuring the interannual variability of Indo-Atlantic exchange has been the major barrier in the investigation of the dynamics and large scale impact of Agulhas leakage. We compute the difference of transport between the Agulhas Current and Agulhas Return Current, which allows us to deduce Agulhas leakage. The main difficulty is to separate the Agulhas Return Current from the southern limb of the subtropical "supergyre" south of Africa. For this purpose, an algorithm that uses absolute dynamic topography data is developed. The algorithm is applied to a state-of-the-art ocean model. The comparison with a Lagrangian method to measure the leakage allows us to validate the new method. An important result is that it is possible to measure Agulhas leakage in this model using the velocity field along a section that crosses both the Agulhas Current and the Agulhas Return Current. In the model a good correlation is found between measuring leakage using the full depth velocities and using only the surface geostrophic velocities. This allows us to extend the method to along-track absolute dynamic topography from satellites. It is shown that the accuracy of the mean dynamic topography does not allow us to determine the mean leakage but that leakage anomalies can be accurately computed.
影响因子：
5.2
作者：
E. van Sebille;A. Biastoch;P. V. van Leeuwen;W. D. de Ruijter
通讯作者：
E. van Sebille;A. Biastoch;P. V. van Leeuwen;W. D. de Ruijter
影响因子：
64.8
作者：
Biastoch, A.;Boening, C. W.;Lutjeharms, J. R. E.
通讯作者：
Lutjeharms, J. R. E.
中尺度扰动控制非洲南部的海洋间交换
影响因子：
5.2
作者：
Biastoch;J. R. E. Lutjeharms;C. W. Böning;M. Scheinert
通讯作者：
M. Scheinert