Spectral and Broadband Albedo of Antarctic Sea-ice Types

反照率或反射系数是测量被照射表面的漫反射系数。以阳光照射的大气作为光源，海冰作为漫反射表面，反照率将是入射光返回大气的比例。完美的（白色）反射面反照率为1；一个完美的（黑色）吸收面反照率为0。海冰反照率用于估算边缘冰带的太阳能收支，用于计算大气环流和地球系统模式中辐射收支中的太阳部分波段，也用于遥感影像数据产品的解译。应用需要反照率进一步进入近红外，出2500nm，假设或近似。现代光谱辐射计，例如将在从霍巴特到南极洲的南大洋航行中使用，可以将这些反照率的测量从350纳米扩展到2500纳米，从而使早期的估计得到验证或纠正。在这次研究巡航中，预计将遇到的表面包括开放水域、脂冰、冰、煎饼冰、年轻的灰冰、年轻的灰白色冰，以及第一年的冰。这些表面上不同数量的雪的存在也令人感兴趣。冰雪中吸收光的杂质，包括黑碳和有机物质（棕色碳），与北极海冰中发现的不同，南极距离燃烧源如此遥远。这可能有助于更好地了解季节周期、能量收支及其在空间范围和厚度上的近期趋势。该项目还将拓宽参与测量活动的美国和澳大利亚学生的教育经验

The albedo, or reflection coefficient, is a measure of the diffuse reflectivity of an irradiated surface. With the sunlit atmosphere as a light source, and sea-ice as a diffuse reflecting surface, the albedo would be the fraction of incident light that is returned to the atmosphere. A perfect (white) reflecting surface would have an albedo of 1; a perfect (black) absorbing surface would have an albedo of 0. The albedo of sea-ice is needed to assess the solar energy budget of the marginal ice zone, to compute the partial solar bands in radiation budgets in general circulation and earth system models, and is also needed to interpret remote sensing imagery data products.Applications requiring albedos further into the near IR, out to 2500nm, are assumed or approximated. Modern spectral radiometers, such as will be used in this campaign on a Southern Ocean voyage from Hobart to Antarctica, can extend these measurements of albedo from 350 to 2500nm, allowing earlier estimates to be verified, or corrected. Surfaces to be encountered on this research cruise are expected to include open water, grease ice, nila ice, pancake ice, young grey ice, young grey-white ice, along with first year ice. The presence of variable amounts of snow on these surfaces is also of interest. Light absorbing impurities in the snow and ice, including black carbon and organic matter (brown carbon) are different from those found in Arctic Sea ice, the Antarctic being so remote from combustion sources. This may allow better understanding of the seasonal cycles, energy budgets and their recent trends in spatial extent and thickness. The project will also broaden the educational experiences of both US and Australian students participating in the measurement campaign