Crucial physical characteristics of sea ice in the Arctic section of 143°–180°W during August and early September 2008
Crucial physical characteristics of sea ice in the Arctic section of 143°–180°W during August and early September 2008
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DOI：
10.1007/s13131-012-0221-0
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发表时间：
2012-08
影响因子：
1.4
通讯作者：
R. Lei;Zhijun Li;Na Li;P. Lu;B. Cheng
中科院分区：
文献类型：
--
作者：
R. Lei;Zhijun Li;Na Li;P. Lu;B. Cheng
2008年8月至9月上旬，对北纬143°~180°W的北极段海冰物理特征进行了调查。船基观测表明，8月30日至9月6日南航期间记录的海冰厚度和浓度均明显小于8月3日至30日北航期间记录的海冰厚度和浓度，特别是在低纬度地区。因此，从8月中旬到9月初，边缘冰区从北纬约74.0°移动到北纬约79.5°。融水池覆盖范围随着纬度的增加而增加，在北纬 84.4° 处达到峰值，大约 27% 的冰被融水池覆盖。在该纬度以上，由于高纬度地区的冰融化季节相对较短，并在8月底开始生长阶段，因此融水池覆盖率明显下降。沿北航区域平均冰厚从75.0°N的0.8（±0.5）m增加到85.0°N的1.5（±0.4）m，而沿南航则迅速减少至78.0°N的0.6（±0.3）m。由于所考察的北极地区冰浓度相对较低且冰层较薄，短期冰站和冰营地只能建立在多年海冰上。根据短期冰站和冰营收集的冰芯对冰特性的观察表明，所有研究的浮冰基本上都是等温的，具有高温和孔隙度高、密度和盐度低的特点。大多数冰的盐度低于 2，平均密度为 800-860 kg/m3。通过与之前的观测结果进行比较，可以确定过去 15 年间所调查的北极地区发生了显着的冰损失。
Sea-ice physical characteristics were investigated in the Arctic section of 143°–180°W during August and early September 2008. Ship-based observations show that both the sea-ice thickness and concentration recorded during southward navigation from 30 August to 6 September were remarkably less than those recorded during northward navigation from 3 to 30 August, especially at low latitudes. Accordingly, the marginal ice zone moved from about 74.0°N to about 79.5°N from mid-August to early September. Melt-pond coverage increased with increasing latitude, peaking at 84.4°N, where about 27% of ice was covered by melt ponds. Above this latitude, melt-pond coverage decreased evidently as the ice at high latitudes experienced a relatively short melt season and commenced its growth stage by the end of August. Regional mean ice thickness increased from 0.8 (±0.5) m at 75.0°N to 1.5 (±0.4) m at 85.0°N along the northward navigation while it decreased rapidly to 0.6 (±0.3) m at 78.0°N along the southward navigation. Because of relatively low ice concentration and thin ice in the investigated Arctic sector, both the short-term ice stations and ice camp could only be set up over multiyear sea ice. Observations of ice properties based on ice cores collected at the short-term ice stations and the ice camp show that all investigated floes were essentially isothermal with high temperature and porosity, and low density and salinity. Most ices had salinity below 2 and mean density of 800–860 kg/m3. Significant ice loss in the investigated Arctic sector during the last 15 a can be identified by comparison with the previous observations.