Physical properties of summer sea ice in the Fram Strait, June-July, 1984
Physical properties of summer sea ice in the Fram Strait, June-July, 1984
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DOI：
10.1029/jc092ic07p06787
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发表时间：
1987-06
期刊：
影响因子：
--
通讯作者：
A. Gow;W. Tucker;W. Weeks
中科院分区：
文献类型：
--
作者：
A. Gow;W. Tucker;W. Weeks
摘要/ Abstract摘要：大部分冰样为多年冰；据估计，按体积计算，它至少占6月和7月从弗拉姆海峡排出的总冰量的84%。厚度和其他性质表明，没有一个多年冰的年龄超过4到5年。多年冰的积雪厚度平均为29厘米，而第一年的积雪厚度平均仅为8厘米。这种差异在很大程度上似乎是由于较薄的第一年冰上的雪升华增强的结果。第一年冰的盐度剖面清楚地显示了持续的盐水排水的影响，在实验中较晚钻探的岩心剖面的含盐量明显低于较早的岩心。多年冰的总体盐度通常比第一年冰的低得多。这种差别为区分两种冰提供了可靠的方法。晶体结构的薄片检查表明，约75%的冰由凝结冰组成，具有典型的柱状晶体结构。剩下的25%由颗粒状冰组成，只有很少的雪冰出现。颗粒冰主要由巴西组成，在浮冰的顶部发现少量，但主要是在多年的山脊上观察到的，它是块间空隙中冰的主要成分。水平取向的晶体c轴呈现出不同程度的排列，从可忽略到强排列，排列方向随深度的变化而变化，这表明在冰生长过程中，冰/水界面上的浮冰相对于洋流的方向发生了变化。
Abstract : Most of the ice sampled was multi-year; it is estimated to represent at least 84% by volume of the total ice discharged from Fram Strait during June and July. Thicknesses and other properties indicated that none of the multi-year ice was older than 4 to 5 years. Snow cover on the multi-year ice averaged 29 cm deep while that on first-year averaged only 8 cm. Much of this difference appears to be the result of enhanced sublimation of the snow on the thinner first-year ice. Salinity profiles of first-year ice clearly show the effects of ongoing brine drainage in that profiles from cores drilled later in the experiment were substantially less saline than earlier cores. Bulk salinities of multi-year ice are generally much lower than those of first-year ice. This difference furnished a reliable means of distinguishing between the two ice types. Thin section examinations of crystal structure indicate that about 75% of the ice consisted of congelation ice with typically columnar crystal structure. The remaining 25% consisted of granular ice with only a few occurrences of snow ice. The granular ice consisted primarily of frazil, found in small amounts at the top of floes, but mainly observed in multi-year ridges where it occurred as the major component of ice in interblock voids. The horizontally oriented crystal c-axes showed varying degrees of alignment, from negligible to strong, in which the alignment direction changed with depth, implying a change in floe orientation with respect to the ocean current at the ice/water interface during ice growth.