极地研究 ›› 2021, Vol. 33 ›› Issue (4): 496-507.DOI: 10.13679/j.jdyj.20210003

• 研究论文 • 上一篇    下一篇

基于Landsat-8的南极蓝冰提取

韦屹1,程晓2,3,4,刘岩1,4,惠凤鸣2,3,4,璩榆桐1,4   

  1. 1北京师范大学全球变化与地球系统科学研究院遥感科学国家重点实验室, 北京 100875;
    2中山大学测绘科学与技术学院, 广东 珠海 519082;
    3南方海洋科学与工程广东省实验室, 广东 珠海 519082;
    4中国高校极地联合研究中心, 北京 100875
  • 收稿日期:2021-01-04 修回日期:2021-03-28 出版日期:2021-12-31 发布日期:2021-12-16
  • 通讯作者: 程晓

Extraction of Antarctic blue ice based on Landsat-8 imagery

Wei Yi1, Cheng Xiao2,3,4, Liu Yan1,4, Hui Fengming2,3,4, Qu Yutong1,4   

  1. 1 State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System
    Science (GCESS), Beijing Normal University, Beijing 100875, China;
    2 School of Geospatial Engineering and Science, Sun Yat-sen University, Zhuhai 519082, China;
    3 Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China;
    4 University Corporation for Polar Research (UCPR), Beijing 100875, China
  • Received:2021-01-04 Revised:2021-03-28 Online:2021-12-31 Published:2021-12-16

摘要: 蓝冰是南极特殊的地表特征, 其低反照率影响着其所在区域乃至整个南极的能量平衡。蓝冰表面消融导致老旧冰层出露, 使其成为研究古气候理想场地。此外, 表面致密坚硬的蓝冰更是建立冰上机场的优选地址。本文提出了快速、有效、自动的蓝冰组合指数法, 将蓝冰指数与阴影指数进行结合来提取南极蓝冰分布。更新的蓝冰数据为南极表面能量平衡变化研究、古气候学研究和蓝冰机场选址提供了新的数据基础。我们利用蓝冰组合指数法对2017—2019年的940景Landsat-8数据进行批量处理, 获取南极82.5°S以北区域的蓝冰分布图, 并用2014年MODIS雪粒径数据获取82.5°S以南的蓝冰分布进行补充得到全南极蓝冰分布。结果表明, 基于Landsat-8的组合指数法南极蓝冰提取结果平均精度可达0.87, 与前人结果具有很好的空间一致性。全南极蓝冰面积为1.7×105 km2, 91.4 %的蓝冰分布在东南极。南极蓝冰主要分布在内陆冰原岛峰、山区的裸岩附近以及近海岸的内陆区域, 其中, 60.4%分布在距离海岸线200 km以内的区域。

关键词: 南极, 蓝冰, Landsat-8, 组合指数法

Abstract: Blue ice, a special surface feature of Antarctica, plays an important role in affecting the energy balance at regional to continental scales owing to its low albedo. Its surface ablation leads to the exposure of old ice, making the blue ice an ideal site for paleoclimate study. In addition, blue ice areas are the preferred landing areas for aircrafts because of its high density and hardness. In this study, we propose a rapid, effective, and automatic blue ice extraction method based on a combined index. Using Landsat-8 imagery, we combined the blue ice index and shadow index to derive the Antarctic blue ice distribution. These updated Antarctic blue ice data provide a new resource for studying the Antarctic surface energy balance, paleoclimatology, and selecting blue ice airport sites. We extracted the blue ice locations north of 82.5°S on the Antarctic from 940 scenes of Landsat-8 imagery between 2017 and 2019, while the blue ice locations south of 82.5°S on the Antarctic were extracted from MODIS snow particle size data from 2014. These data were used to map the blue ice distribution over the whole of Antarctica. Results showed that using Landsat-8 imagery, the average accuracy of the blue ice combined index method reached 0.87. The resulting blue ice distribution on the Antarctic is spatially consistent with previous results. The total area of Antarctic blue ice is about 1.7 ×105 km2, 91.4% of which occurs in East Antarctica. Blue ice areas mainly exist near exposed nunataks or mountains,as well as coastal areas. About 60.4% of the Antarctic blue ice occurs within the inland from its coastline to 200 km southward.

Key words: Antarctic, blue ice, Landsat-8, combined index method