Blue-ice areas in Antarctica derived from NOAA AVHRR satellite data
Blue-ice areas in Antarctica derived from NOAA AVHRR satellite data
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DOI：
10.3189/172756501781832386
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发表时间：
2001
影响因子：
3.4
通讯作者：
J. Winther;M. Jespersen;G. Liston
中科院分区：
文献类型：
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作者：
J. Winther;M. Jespersen;G. Liston
摘要利用美国地质调查局建立的美国国家海洋和大气管理局（NOAA）先进甚高分辨率辐射计（AVHRR）南极洲无云图像拼接，绘制了南极蓝冰区地图。这幅马赛克由1980年至1994年拍摄的38幅场景组成。我们的研究结果表明，“融致”和“风致”这两种主要类型的蓝冰各有大约6万平方公里的面积。通常，前一种类型位于沿海地区的斜坡上，那里的气候条件（即持续的风和温度）以及有利的地表朝向维持了地表和近地表融化的条件。后一种蓝冰类型发生在山脉附近或冰川出口处，通常在海拔较高的地方，那里持续的风一年四季都在侵蚀积雪，并与升华相结合，形成净消融区。此外，我们还确定了另外12.1万平方公里可能存在蓝冰的面积。然而，在这些地区的特征，如混合像素，釉面雪面，裂缝和/或阴影使解释更加不确定。总之，用这种方法对南极蓝冰面积覆盖率的保守估计为12万平方公里（占南极大陆的0.8%），潜在最大值为24.1万平方公里（占南极大陆的1.6%）。
Abstract We have mapped Antarctic blue-ice areas using the U.S. National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) Antarctica cloud-free image mosaic established by the United States Geological Survey. The mosaic consists of 38 scenes acquired from 1980 to 1994. Our results show that approximately 60 000 km2 of blue ice exist for each of the two main types of blue ice: “melt-induced” and “wind-induced”. Normally, the former type is located on slopes in coastal areas where climate conditions (i.e. persistent winds and temperature), together with favourable surface orientation, sustain conditions for surface and near surface melt. The latter blue-ice category occurs near mountains or on outlet glaciers, often at higher elevations, where persistent winds erode snow away year-round, and combined with sublimation creates areas of net ablation. Furthermore, we have identified an additional area of 121 000 km2 as having potential for blue ice. However, in these areas features such as mixed pixels, glazed snow surfaces, crevasses and/or shadows make interpretation more uncertain. In conclusion, a conservative estimate of Antarctic blue-ice area coverage by this method is found to be 120 000 km2 (∼0.8% of the Antarctic continent), with a potential maximum of 241 000 km2 (∼1.6% of the Antarctic continent).