Antarctic Sea Ice Extent

Areas of the ocean that have frozen are considered “sea ice,” and can vary from slushy, barely solid areas to sheets of ice that are meters thick. Since the late 1970s, satellites have been used to monitor both the extent and concentration of sea ice around the world. Each day, the National Snow and Ice Data Center generates sea ice extent analyses from a variety of microwave satellite data sources. A smoothing algorithm is applied to the original shapefiles accessed from NSIDC. This layer is best shown when using an Antarctic polar projection. See Antarctic Sea Ice and Median Extent Map as an example. Another layer shows sea ice extent for the Arctic. Data Source National Snow and Ice Data Center Click for HTTPS data access Select "Download Data" tab Click "Go to FTP" button Navigate popup to sub-folder: "south/monthly/shapefiles" Provider Terms of Use Revisions Apr 8, 2026: Updated field details to include descriptions and value types Sep 9, 2025: Data updates have been restored using NOAA data link provided by NSIDC海洋中发生冻结的区域被称为“海冰（sea ice）”，其形态可从稀软、近乎未完全固结的区域，变化至厚度达数米的完整冰盖。自20世纪70年代末以来，科研人员已借助卫星对全球海冰的范围与浓度开展监测。美国国家雪冰数据中心（National Snow and Ice Data Center，NSIDC）每日会基于多类微波卫星数据源生成海冰范围分析成果。研究人员会对从NSIDC获取的原始形状文件（shapefiles）应用平滑算法。该图层在采用南极极投影时可视化效果最佳，可参考《南极海冰与中位数范围地图》作为示例。另有一个图层用于展示北极地区的海冰范围。数据来源：美国国家雪冰数据中心。HTTPS数据获取方式：点击进入相关页面后，选择「下载数据」标签页，点击「前往FTP」按钮，在弹出的窗口中导航至子文件夹「south/monthly/shapefiles」。提供者使用条款 修订记录：2026年4月8日：更新字段详情，新增字段描述与数值类型说明；2025年9月9日：已通过NSIDC提供的NOAA数据链接恢复数据更新服务。