A Spatiotemporal Comparison and Assessment of Multisource Satellite Derived Sea Ice Thickness in the Arctic Thinner Ice Region

The accuracy and reliability of the latest version of multisource satellite derived Arctic sea ice thickness (SIT) in thinner ice regions are currently uncertain. This study integrated a comprehensive comparison and assessment of Arctic SIT derived from CryoSat-2, Soil Moisture and Ocean Salinity (SMOS), fusions of CryoSat-2 and SMOS (CS2SMOS), and Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) during 2011-2022. The focus was on the region with mean SIT less than 1 m. The five datasets from the Operation IceBridge L4 and Quick Look, IceBird campaign, CryoSat Validation Experiment, and the Canadian Arctic Archipelago stations were utilized as the reference data in the assessment. The four satellite products could capture similar major spatiotemporal variations in SIT. During 2011-2022, CryoSat-2 generally derived the largest multiyear mean SIT, followed by CS2SMOS, and SMOS exhibited the smallest mean. During 2018-2022, ICESat-2 recorded the largest mean SIT and the rankings of the other three satellite products remained consistent. The comparison and assessment results indicated that all four satellite products generally exhibited some underestimations of SIT. During 2011-2022, the comprehensive results highlighted CryoSat-2 as the best overall performance product, exhibiting optimal agreement with all five reference datasets. During 2018-2022, CryoSat-2 consistently demonstrated the best overall performance. CS2SMOS exhibited a performance similar to CryoSat-2 in the two selected periods. This study contributes to further understandings of reliabilities and potential disparities among the latest versions of multisource satellite products in the thinner ice region.