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The determination of thin-ice thickness (TIT) in the Arctic can not only contribute to the understanding of climate change, but also to the ship navigation in the Arctic Passages. Currently, the acquisition of high-resolution distribution of TIT is primarily facilitated by thermal measurements derived from a one-dimensional (1-D) thermodynamic ice model. This study obtained spaceborne records over the Bering Sea and the Chukchi Sea for the last five years (2020−2024). The performance of this model is significantly influenced by the temperature of air (Ta), ice surface (Ts), and seawater freezing point (Tw). The TIT retrieval results demonstrate a high accuracy when compared with operational sea ice thickness products derived by microwave measurements (i.e. SMOS). The mean absolute difference between the two is ~0.04 m, and the TIT range of 0−0.2 m exhibits the most reliable accuracy. However, the sensitivity of this model is not applicable during the melt season with rising temperature and inhomogeneous sea ice cover. This limitation can be overcome through the development of an optical model based on the relationship between TIT and reflectivity characteristics. Additionally, notable discrepancies have been revealed between the spatial patterns of TIT retrieval results using optical and thermal measurements, particularly in regions with excessive sensitivity for the thermodynamic model when the temperature difference between the air and ice surface is minimal. The updated schemes for TIT retrieval can effectively compensate for the absence of high-resolution ice thickness products during the melt season, thereby further facilitating the long-term quantification of TIT.
Suo et al. (Wed,) studied this question.