Abstract. The wave-affected marginal ice zone (MIZ) is an essential part of the sea ice cover and crucial to the atmosphere–ice–ocean interaction in the polar region. While we primarily rely on in situ campaigns for studying MIZs, significant challenges exist for the remote sensing of MIZs by satellites. This study develops a novel retrieval algorithm for wave-affected MIZs based on the delay-Doppler radar altimeter on board CryoSat-2 (CS2). CS2 waveform power and waveform stack statistics are used to determine the part of the sea ice cover affected by waves. Based on the CS2 data since 2010, we generate a climate record of wave-affected MIZs in the Atlantic Arctic, spanning 12 winters between 2010 and 2022 (https://doi.org/10.5281/zenodo.8176585, Zhu et al., 2023). The MIZ record indicates no significant change in the mean MIZ width or the extreme width, although large temporal and spatial variability is present. In particular, extremely wide MIZ events (over 300 km) are observed in the Barents Sea, whereas in other parts of the Atlantic Arctic, MIZ events are typically narrower. We also compare the CS2-based retrieval with the retrievals based on the laser altimeter of ICESat2 and the synthetic aperture radar images from Sentinel-1. Under spatial and temporal collocation, we attain good agreement among the MIZ retrievals based on the three different types of satellite payloads. Moreover, the traditional sea-ice-concentration-based definition of MIZ yields systematically narrower MIZs than CS2, and no statistically significant correlation exists between the two. Beyond its application to CS2, the proposed retrieval algorithm can be adapted to historical and future radar altimetry campaigns. The synergy of multiple satellites can improve the spatial and temporal representation of the altimeters' observation of the MIZs.

中文翻译：

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基于 CryoSat-2 的大西洋北极冬季海浪影响边缘冰区 12 年气候记录


摘要。受波浪影响的边缘冰区（MIZ）是海冰覆盖的重要组成部分，对极地地区的大气-冰-海洋相互作用至关重要。虽然我们主要依靠实地活动来研究 MIZ，但卫星遥感 MIZ 仍存在重大挑战。本研究基于 CryoSat-2 (CS2) 上的延迟多普勒雷达高度计，开发了一种新颖的受波影响 MIZ 的检索算法。 CS2波形功率和波形叠加统计数据用于确定受波浪影响的海冰覆盖部分。根据 2010 年以来的 CS2 数据，我们生成了 2010 年至 2022 年 12 个冬季大西洋北极地区受海浪影响的 MIZ 的气候记录（https://doi.org/10.5281/zenodo.8176585，Zhu 等人， 2023）。 MIZ 记录表明，尽管存在较大的时间和空间变化，但平均 MIZ 宽度或极端宽度没有显着变化。特别是，在巴伦支海观察到极宽的 MIZ 事件（超过 300 公里），而在大西洋北极的其他地区，MIZ 事件通常较窄。我们还将基于 CS2 的反演与基于 ICESat2 激光高度计和 Sentinel-1 合成孔径雷达图像的反演进行了比较。在时空搭配下，我们基于三种不同类型的卫星有效载荷的 MIZ 反演取得了良好的一致性。此外，传统的基于海冰浓度的 MIZ 定义系统产生的 MIZ 比 CS2 更窄，并且两者之间不存在统计上显着的相关性。除了应用于 CS2 之外，所提出的检索算法还可以适应历史和未来的雷达测高活动。 多颗卫星的协同作用可以改善高度计观测 MIZ 的空间和时间表征。