Abstract The ocean mean dynamic topography (MDT) is the surface representation of the ocean circulation. The MDT may be determined by the ocean approach, which involves temporal averaging of numerical ocean circulation model information, or by the geodetic approach, wherein the MDT is derived using the ellipsoidal height of the mean sea surface (MSS), or mean sea level (MSL) minus the geoid as the geoid. The ellipsoidal height of the MSS might be estimated either by satellite or coastal tide gauges by connecting the tide gauge datum to the Earth-centred reference frame. In this article we present a novel approach to improve the coastal MDT, where the solution is based on both satellite altimetry and tide gauge data using new set of 302 tide gauges with ellipsoidal heights through the SONEL network. The approach was evaluated for the Northeast Atlantic coast where a dense network of GNSS-surveyed tide gauges is available. The typical misfit between tide gauge and satellite or oceanographic MDT was found to be around 9 cm. This misfit was found to be mainly due to small scale geoid errors. Similarly, we found, that a single tide gauge places only weak constraints on the coastal dynamic topography.

中文翻译：

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测潮仪和卫星测高相结合改善沿海平均动力地形

摘要 海洋平均动态地形（MDT）是海洋环流的表面表征。MDT 可以通过海洋方法确定，它涉及数值海洋环流模型信息的时间平均，或通过大地测量方法确定，其中 MDT 是使用平均海面 (MSS) 的椭球高度或平均海平面 ( MSL) 减去大地水准面作为大地水准面。MSS 的椭球体高度可以通过卫星或沿海潮汐测量仪通过将潮汐测量仪基准连接到地心参考系来估计。在本文中，我们提出了一种改进沿海 MDT 的新方法，该解决方案基于卫星高度测量和潮汐计数据，使用新的 302 个具有椭球高度的潮汐计，通过 SONEL 网络。该方法针对东北大西洋沿岸进行了评估，那里有密集的 GNSS 测量的潮汐测量仪网络可用。发现潮汐计和卫星或海洋学 MDT 之间的典型错配约为 9 厘米。发现这种失配主要是由于小规模的大地水准面误差。同样，我们发现，单个潮汐计对沿海动态地形的约束很弱。