Abstract. A new Mean Sea Surface (MSS) called DTU21MSS for referencing sea level anomalies from satellite altimetry is introduced in this paper and a suite of evaluations are performed. One of the reasons for updating the existing Mean Sea Surface is the fact, that during the last 6 years nearly three times as much data have been made available by the space agencies, resulting in more than 15 years of altimetry from Long Repeat Orbits or Geodetic Missions. This includes the two interleaved long repeat cycles of Jason-2 with a systematic cross-track distance as low as 4 km. A new processing chain with updated filtering and editing has been implemented for DTU21MSS. This way, the DTU21MSS has been computed from 2 Hz altimetry in contrast to the former DTU15MSS/DTU18MSS which were computed from 1 Hz altimetry. The new DTU21MSS is computed over the same 20-year averaging time from 1993.01.01 to 2012.12.31 with a well-specified central time of 2003.01.01 and is available from the following site; (https://doi.org/10.11583/DTU.19383221.v1, Andersen, 2022) Cryosat-2 employs SAR and SARin modes in a large part of the Arctic Ocean due to the presence of sea ice. For SAR and SARin mode data we applied the SAMOSA+ physical retracking in order to make it compatible with the physical retracker used for conventional Low-Resolution Mode data in other parts of the ocean.

中文翻译：

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DTU21 全球平均海面及首次评估

摘要。本文介绍了一种称为 DTU21MSS 的新平均海面 (MSS)，用于参考卫星测高的海平面异常，并进行了一系列评估。更新现有平均海面的原因之一是，在过去 6 年中，空间机构提供的数据量几乎是原来的三倍，这导致长重复轨道或大地测量的高度测量超过 15 年任务。这包括 Jason-2 的两个交错的长重复周期，系统交叉轨道距离低至 4 公里。已为 DTU21MSS 实施了具有更新的过滤和编辑的新处理链。这样，DTU21MSS 是根据 2 Hz 测高法计算的，而之前的 DTU15MSS/DTU18MSS 是根据 1 Hz 测高法计算的。新的 DTU21MSS 是在从 1993.01.01 到 2012.12.31 的相同 20 年平均时间内计算得出的，其中明确指定的中心时间为 2003.01.01，可从以下站点获得；(https://doi.org/10.11583/DTU.19383221.v1, Andersen, 2022) 由于海冰的存在，Cryosat-2 在北冰洋的大部分地区使用 SAR 和 SARin 模式。对于 SAR 和 SARin 模式数据，我们应用了 SAMOSA+ 物理重跟踪，以使其与用于海洋其他部分的传统低分辨率模式数据的物理重跟踪器兼容​​。