With the assimilation of satellite-based sea-ice thickness (SIT) data, the new SIT reanalysis from the Towards an Operational Prediction system for the North Atlantic European coastal Zones (TOPAZ4) was released from 2014 to 2018. Apart from assimilating sea-ice concentration and oceanic variables, TOPAZ4 further assimilates CS2SMOS SIT. In this study, the 5-year reanalysis is compared with CS2SMOS, the Pan-Arctic Ice-Ocean Modeling and Assimilating System (PIOMAS) and the Combined Model and Satellite Thickness (CMST). Moreover, we evaluate TOPAZ4 SIT with field observations from upward-looking sonar (ULS), ice mass-balance buoys, Operation IceBridge Quicklook and Sea State Ship-borne Observations. The results indicate TOPAZ4 well reproduces the spatial characteristics of the Arctic SIT distributions, with large differences with CS2SMOS/PIOMAS/CMST mainly restricted to the Atlantic Sector and to the month of September. TOPAZ4 shows thinner ice in March and April, especially to the north of the Canadian Arctic Archipelago with a mean bias of −0.30 m when compared to IceBridge. Besides, TOPAZ4 simulates thicker ice in the Beaufort Sea when compared to ULS, with a mean bias of 0.11 m all year round. The benefit from assimilating SIT data in TOPAZ4 is reflected in a 34% improvement in root mean square deviation.

中文翻译：

---

来自海-海-冰耦合数据同化系统 TOPAZ4 的海冰厚度再分析数据评估

随着基于卫星的海冰厚度 (SIT) 数据的同化，2014 年至 2018 年发布了来自北大西洋欧洲沿海地区业务预测系统 (TOPAZ4) 的新 SIT 再分析。除了同化海冰浓度和海洋变量，TOPAZ4 进一步同化 CS2SMOS SIT。在这项研究中，将 5 年再分析与 CS2SMOS、泛北极冰海建模和同化系统 (PIOMAS) 以及组合模式和卫星厚度 (CMST) 进行了比较。此外，我们通过仰视声纳 (ULS)、冰质量平衡浮标、冰桥快速查看和海况船载观测的现场观测来评估 TOPAZ4 SIT。结果表明 TOPAZ4 很好地再现了北极 SIT 分布的空间特征，与 CS2SMOS/PIOMAS/CMST 的巨大差异主要限于大西洋区和 9 月份。TOPAZ4 在 3 月和 4 月显示出较薄的冰层，尤其是在加拿大北极群岛北部，与 IceBridge 相比，平均偏差为 -0.30 m。此外，与 ULS 相比，TOPAZ4 模拟了波弗特海中更厚的冰层，全年平均偏差为 0.11 m。在 TOPAZ4 中同化 SIT 数据的好处体现在均方根偏差提高了 34%。全年 11 m。在 TOPAZ4 中同化 SIT 数据的好处体现在均方根偏差提高了 34%。全年 11 m。在 TOPAZ4 中同化 SIT 数据的好处体现在均方根偏差提高了 34%。