Thin sea ice thickness data set in the Arctic Ocean

High ice production in coastal polynyas over the continental shelves in the Arctic Ocean is responsible for the formation of cold saline water, which contributes to the maintenance of the Arctic Ocean halocline. The accurate detection of coastal polynyas, including an estimate of thin ice thickness, is essential for the estimation of sea ice production. We have developed an algorithm that estimates thin ice thickness using Special Sensor Microwave/Imager (SSM/I) data in the Arctic Ocean. Detection and estimation of sea ice thicknesses of <0.15 m are based on the SSM/I 85 and 37 GHz polarization ratios (PR85 and PR37) through a comparison with sea ice thicknesses estimated from the advanced very high resolution radiometer (AVHRR) data in the three different Arctic coastal polynyas. Thus, for the entire Arctic Ocean, the algorithm can be used for the detection of coastal polynyas and for the estimation of sea ice production through combination with heat-flux calculation. We provide the first circumpolar mapping of sea ice production in coastal polynyas over the entire Arctic Ocean.

北冰洋大陆架海域的海岸冰间湖（coastal polynya）中高强度的海冰生成过程，是冷盐水团形成的核心驱动因素，而冷盐水团对北冰洋盐跃层（halocline）的维持具有关键贡献。精准探测海岸冰间湖并估算其薄冰厚度，是海冰生成量估算的必要前提。本研究基于专用传感器微波成像仪（Special Sensor Microwave/Imager，SSM/I）数据，开发了一套北冰洋薄冰厚度估算算法。针对厚度小于0.15米的海冰，研究通过对比三个不同北极海岸冰间湖中由先进甚高分辨率辐射计（Advanced Very High Resolution Radiometer，AVHRR）数据反演得到的海冰厚度，确立了基于SSM/I传感器85 GHz与37 GHz波段极化比（PR85与PR37）的反演方法。因此，结合热通量计算方法，该算法可推广至整个北冰洋海域，用于海岸冰间湖的探测以及海冰生成量的估算。本研究首次完成了全北冰洋范围内海岸冰间湖海冰生成量的环极制图。