Abstract Sea level observations suggest that western boundary currents, such as the Gulf Stream, contribute to coastal sea-level variability and rise. Since the influence of the Agulhas Current on coastal sea-level variability and rise has not yet been quantified, this study considers how variations in the transport and position of this current affect sea-level variability along the South African coast. This was achieved by analysing timescales of variability in the time series of an Agulhas Current transport proxy and absolute dynamic topography at the core position, at the ACT array, comparing these to monthly mean sea level records of East London (33°S, 28°E). The timescales embedded in each of the datasets were separated through the Empirical Mode Decomposition (EMD) method. Monthly gridded satellite altimetry sea level anomalies were also utilised to extend the analysis to other tide gauge locations on the east and south coast of South Africa. The results suggest that, on timescales ranging from a few months to decades, coastal sea-level is associated with the Agulhas Current through absolute dynamic topography variations in the Agulhas Current core. Absolute dynamic topography variations in the Agulhas Current core are found to be in response to displacements of the current both near and offshore from the coast during eddies and meandering events. The study suggests that the Agulhas Current variations should be taken into account for better coastal planning, management and engineering.

中文翻译：

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南非沿海海平面变化与厄加勒斯海流的关系

摘要 海平面观测表明，西部边界流，如墨西哥湾流，有助于沿海海平面的变化和上升。由于厄加勒斯海流对沿海海平面变化和上升的影响尚未量化，本研究考虑了该海流的运输和位置的变化如何影响沿南非海岸的海平面变化。这是通过分析 ACT 阵列核心位置的 Agulhas Current 传输代理和绝对动态地形的时间序列变化的时间尺度，并将这些与东伦敦（33°S，28°）的月平均海平面记录进行比较来实现的E)。嵌入在每个数据集中的时间尺度通过经验模式分解 (EMD) 方法分离。每月网格化的卫星测高海平面异常也被用来将分析扩展到南非东海岸和南海岸的其他潮汐测量位置。结果表明，在几个月到几十年的时间尺度上，沿海海平面通过厄加勒斯海流核心的绝对动态地形变化与厄加勒斯海流相关联。发现 Agulhas Current 核心中的绝对动态地形变化是对涡流和蜿蜒事件期间海岸附近和离岸海流位移的响应。该研究表明，为了更好地进行沿海规划、管理和工程，应考虑到阿古拉斯海流的变化。在从几个月到几十年不等的时间尺度上，沿海海平面通过厄加勒斯海流核心的绝对动态地形变化与厄加勒斯海流相关联。发现 Agulhas Current 核心中的绝对动态地形变化是对涡流和蜿蜒事件期间海岸附近和离岸海流位移的响应。该研究表明，为了更好地进行沿海规划、管理和工程，应考虑到阿古拉斯海流的变化。在从几个月到几十年不等的时间尺度上，沿海海平面通过厄加勒斯海流核心的绝对动态地形变化与厄加勒斯海流相关联。发现 Agulhas Current 核心中的绝对动态地形变化是对涡流和蜿蜒事件期间海岸附近和离岸海流位移的响应。该研究表明，为了更好地进行沿海规划、管理和工程，应考虑到阿古拉斯海流的变化。发现 Agulhas Current 核心中的绝对动态地形变化是对涡流和蜿蜒事件期间海岸附近和离岸海流位移的响应。该研究表明，为了更好地进行沿海规划、管理和工程，应考虑到阿古拉斯海流的变化。发现 Agulhas Current 核心中的绝对动态地形变化是对涡流和蜿蜒事件期间海岸附近和离岸海流位移的响应。该研究表明，为了更好地进行沿海规划、管理和工程，应考虑到阿古拉斯海流的变化。