The physical structures of snow and sea ice in the Arctic section of 150°-180°W during the summer of 2010
The physical structures of snow and sea ice in the Arctic section of 150°-180°W during the summer of 2010
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DOI：
10.1007/s13131-013-0314-4
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发表时间：
2013-05
影响因子：
1.4
通讯作者：
Wenfeng Huang;R. Lei;Matero Ilkka;Qun Li;Yongxue Wang;Zhijun Li
中科院分区：
文献类型：
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作者：
Wenfeng Huang;R. Lei;Matero Ilkka;Qun Li;Yongxue Wang;Zhijun Li
2010年7月下旬至8月下旬，在雪坑、冰芯和钻孔测量的基础上，对150°~ 180°W北极地区的雪和海冰的物理结构进行了观测。几乎所有被调查的浮冰都是第一年形成的冰，除了阿拉斯加北部的一块浮冰，它可能是初夏从加拿大北极群岛北部运来的多年冰。所有被调查浮冰上的积雪都处于融化阶段，温度接近0°C，密度为295-398 kg/m3。积雪可以分为两到五层不同的纹理，大多数情况下，顶层是新鲜的雪，中间是圆粒层，底部是雪泥和/或薄的冰霜层。第一年的海冰顶部含有约7%-17%的颗粒冰。在下层没有粒状冰。海冰的内部融化和淡化带来了强烈的温度、盐度、密度、气体和盐水体积分数的分层。海冰温度随深度呈线性冷却，盐度和密度随归一化深度呈线性增加，分别为0.2 ~ 0.9和0 ~ 0.65。上层，尤其是干舷层，盐度和密度最低，因此气含量最大，卤水含量最小。由于样品间冰孔隙度差异较大，冰基底层的盐度和密度高度分散。总体平均海冰温度为−0.8℃，盐度为1.8，密度为837 kg/m3，气体和盐水体积分数为9.3%和10.4%。8月中旬，位于北纬87°、西经175°的被调查浮冰的积雪、海冰底部和海冰内部显示出融化的迹象。
The physical structures of snow and sea ice in the Arctic section of 150°–180°W were observed on the basis of snow-pit, ice-core, and drill-hole measurements from late July to late August 2010. Almost all the investigated floes were first-year ice, except for one located north of Alaska, which was probably multi-year ice transported from north of the Canadian Arctic Archipelago during early summer. The snow covers over all the investigated floes were in the melting phase, with temperatures approaching 0 °C and densities of 295–398 kg/m3. The snow covers can be divided into two to five layers of different textures, withmost cases having a top layer of fresh snow, a round-grain layer in themiddle, and slush and/or thin icing layers at the bottom. The first-year sea ice contained about 7%–17% granular ice at the top. There was no granular ice in the lower layers. The interiormelting and desalination of sea ice introduced strong stratifications of temperature, salinity, density, and gas and brine volume fractions. The sea ice temperature exhibited linear cooling with depth, while the salinity and the density increased linearly with normalized depth from 0.2 to 0.9 and from 0 to 0.65, respectively. The top layer, especially the freeboard layer, had the lowest salinity and density, and consequently the largest gas content and the smallest brine content. Both the salinity and density in the ice basal layer were highly scattered due to large differences in ice porosity among the samples. The bulk average sea ice temperature, salinity, density, and gas and brine volume fractions were −0.8 °C, 1.8, 837 kg/m3, 9.3% and 10.4%, respectively. The snow cover, sea ice bottom, and sea ice interior show evidences of melting duringmid-August in the investigated floe located at about 87°N, 175°W.