MOSAiC drift expedition from October 2019 to July 2020: sea ice conditions from space and comparison with previous years
MOSAiC drift expedition from October 2019 to July 2020: sea ice conditions from space and comparison with previous years
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DOI：
10.5194/tc-15-3897-2021
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发表时间：
2021-08-20
期刊：
影响因子：
5.2
通讯作者：
Sokolova, Julia
中科院分区：
文献类型：
--
作者：
Krumpen, Thomas;von Albedyll, Luisa;Sokolova, Julia
我们结合联合收割机卫星数据产品，提供了国际多学科漂流观测站北极气候研究（MOSAiC）考察的物理海冰条件沿着漂移的初步和总体概述，并与往年（2005-2006年至2018-2019年）进行了比较。我们发现，MOSAiC漂移速度比气候平均漂移快20%左右，作为一月至三月期间在Barents-Kara-Laptev海域周围盛行的大规模低压异常的结果。在冬季（10月至4月），卫星观测表明，与沿着同一轨迹的前几年相比，中央天文台附近（CO;半径50公里）的海冰相当薄。与冰层厚度不同，卫星得出的海冰浓度、铅含量和冬季积雪厚度接近长期平均值，变化不大。随着春天的到来和距离弗拉姆海峡的减少，冰浓度和铅活性的变化增加。此外，夏季的形变事件（辐散、辐合和切变）的频率和强度均高于冬季。总的来说，我们发现，海冰条件下观察到的CO 5公里的距离是代表更广泛的（50和100公里）的环境。一个例外是冰的厚度;在这里，我们发现，在50公里半径的CO海冰比海冰薄100公里半径内的一个小的，但连续的月平均值一致的因素（4%）。此外，卫星数据表明，MOSAiC浮冰上的大型融化池的形成早于邻近浮冰。
We combine satellite data products to provide a first and general overview of the physical sea ice conditions along the drift of the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and a comparison with previous years (2005-2006 to 2018-2019). We find that the MOSAiC drift was around 20% faster than the climatological mean drift, as a consequence of large-scale low-pressure anomalies prevailing around the Barents-Kara-Laptev sea region between January and March. In winter (October-April), satellite observations show that the sea ice in the vicinity of the Central Observatory (CO; 50 km radius) was rather thin compared to the previous years along the same trajectory. Unlike ice thickness, satellite-derived sea ice concentration, lead frequency and snow thickness during winter months were close to the long-term mean with little variability. With the onset of spring and decreasing distance to the Fram Strait, variability in ice concentration and lead activity increased. In addition, the frequency and strength of deformation events (divergence, convergence and shear) were higher during summer than during winter. Overall, we find that sea ice conditions observed within 5 km distance of the CO are representative for the wider (50 and 100 km) surroundings. An exception is the ice thickness; here we find that sea ice within 50 km radius of the CO was thinner than sea ice within a 100 km radius by a small but consistent factor (4 %) for successive monthly averages. Moreover, satellite acquisitions indicate that the formation of large melt ponds began earlier on the MOSAiC floe than on neighbouring floes.