Investigations of newly formed sea ice in the Cape Bathurst polynya: 1. Structural, physical, and optical properties
Investigations of newly formed sea ice in the Cape Bathurst polynya: 1. Structural, physical, and optical properties
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巴瑟斯特角冰间湖新形成海冰的调查： 1. 结构、物理和光学特性
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Barber
中科院分区：
文献类型：
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作者：
J. Ehn;B. Hwang;R. Galley;D. Barber
[1] 2003 年 10 月至 11 月初秋季结冰期间，对巴瑟斯特角冰间湖（北纬 71°，西经 127°）新形成的冰类型的物理、结构和光学特性进行了研究。多变的气象条件和偶尔的降雪导致了众多冰类型和表面条件的形成。冰样本是从代表该区域的水平均匀表面收集的。对 33 个冰芯的晶体学分析揭示了该地区高度可变的生长条件和形成机制。颗粒冰的平均比例为 33%，中间颗粒柱状冰和柱状冰分别占 37% 和 30%。冰中的盐度分布呈 C 形，并且随着冰变厚，整体盐度按照 4.582 + 13.358/hi (cm) 下降。这些条件导致盐水体积在 4% 到 46% 之间。由于盐水的排出，裸露的冰表面通常形成高盐度的盐水撇层。在该层中观察到盐度高达 40‰。在适当的条件下，冰上会形成霜花，其存在与冰的微结构特征有关，晶体呈圆盘状。当雪与表面盐水融合并在雪/冰界面处形成复杂的超盐表面时，就形成了细粒雪冰。薄冰类型的光谱反射率与表面条件密切相关。霜花的存在显着增加了反射率，与降雪量无关。一旦存在 20-30 毫米厚的雪层，冰厚度的任何增加都对反射率几乎没有影响。
[1] The physical, structural, and optical properties of newly formed ice types were studied in the Cape Bathurst polynya (71°N, 127°W) during fall freezeup in October to early November 2003. Variable meteorological conditions with occasional snowfall resulted in the formation of numerous ice types and surface conditions. Ice samples were collected from horizontally homogeneous surfaces representative of the area. Crystallographic analysis on 33 ice cores revealed highly variable growth conditions and formation mechanisms in the area. The mean fraction of granular ice was 33%, while intermediate granular-columnar and columnar ice contributed 37% and 30%, respectively. Salinity profiles in the ice were C-shaped and as the ice grew thicker, bulk salinities decreased according to 4.582 + 13.358/hi (cm). These conditions resulted in brine volumes ranging from 4% to 46%. Bare ice surfaces commonly formed a high salinity brine skim layer due to brine expulsion. Salinities up to 40‰ were observed in this layer. Under suitable conditions frost flowers formed on the ice, and their presence was related to characteristic ice microstructure with crystals that appeared disc-like in shape. Fine-grained snow-ice was formed when snow merged with surface brine to create a complex hypersaline surface at the snow/ice interface. The spectral reflectance for the thin ice types was most strongly related to surface conditions. The presence of frost flowers significantly increased the reflectance independent of snow precipitation. Any increase in ice thickness was found to have little effect on the reflectance once a 20–30 mm thick snow layer was present.