De Carolis Giacomo, Olla Piero, De Santi Francesca
National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Milan, 20133, Italy.
National Research Council of Italy (CNR), Institute of Atmospheric Science and Climate (ISAC), Cagliari, 09042, Italy.
Sci Rep. 2021 Feb 1;11(1):2733. doi: 10.1038/s41598-021-82228-x.
Young sea ice composed of grease and pancake ice (GPI), as well as thin floes, considered to be the most common form of sea ice fringing Antarctica, is now becoming the "new normal" also in the Arctic. A study of the rheological properties of GPI is carried out by comparing the predictions of two viscous wave propagation models: the Keller model and the close-packing (CP) model, with the observed wave attenuation obtained by SAR image techniques. In order to fit observations, it is shown that describing GPI as a viscous medium requires the adoption of an ice viscosity which increases with the ice thickness. The consequences regarding the possibility of ice thickness retrieval from remote sensing data of wave attenuation are discussed. We provide examples of GPI thickness retrievals from a Sentinel-1 C band SAR image taken in the Beaufort Sea on 1 November 2015, and three CosmoSkyMed X band SAR images taken in the Weddell Sea on March 2019. The estimated GPI thicknesses are consistent with concurrent SMOS measurements and available local samplings.
由油脂状冰和饼状冰（GPI）以及薄冰 floes 组成的年轻海冰，被认为是南极洲边缘最常见的海冰形式，如今在北极也正成为“新常态”。通过比较两种粘性波传播模型（凯勒模型和紧密堆积（CP）模型）的预测结果与利用合成孔径雷达（SAR）图像技术获得的观测波衰减，对 GPI 的流变特性进行了研究。为了拟合观测结果，研究表明，将 GPI 描述为粘性介质需要采用随冰厚度增加而增大的冰粘度。讨论了从波衰减遥感数据反演冰厚度可能性的相关后果。我们给出了从 2015 年 11 月 1 日在波弗特海拍摄的哨兵 -1 C 波段 SAR 图像以及 2019 年 3 月在威德尔海拍摄的三张宇宙天空测量 X 波段 SAR 图像中反演 GPI 厚度的示例。估计的 GPI 厚度与同期的土壤湿度和海洋盐度卫星观测计划（SMOS）测量结果以及可用的当地采样结果一致。
