This story is an update to the Antarctic sea ice feature in our World of Change series tracking long-term change on Earth’s surface through satellite imagery.
这个故事是我们的“变化世界”系列中南极海冰特征的更新，该系列通过卫星图像跟踪地球表面的长期变化。
Unlike the Arctic—an ocean basin surrounded by land—the Antarctic is a large continent surrounded by an ocean. Because of this geography, sea ice has more room to expand during the winter. However, that ice also stretches into warmer latitudes, leading to more melting in the summer. Antarctic sea ice usually peaks in September, around the end of the Southern Hemisphere’s winter, and retreats to a minimum in February.
与北极（一个被陆地包围的海洋盆地）不同，南极洲是一个被海洋包围的大大陆。由于这种地理位置，海冰在冬季有更大的扩展空间。然而，这些冰也会延伸到温暖的纬度，导致夏季更多的融化。南极海冰通常在九月（南半球冬季结束前后）达到顶峰，并在二月降至最低点。
According to NASA and the National Snow and Ice Data Center (NSIDC), Antarctic sea ice in 2026 likely reached its annual maximum extent on September 14 (above). On that date, the ice covered an estimated 17.59 million square kilometers (6.79 million square miles), making it the third-lowest maximum on record.
根据 NASA 和国家冰雪数据中心 (NSIDC) 的数据，2026 年南极海冰可能会在 9 月 14 日达到年度最大范围（上图）。当天，冰层覆盖面积估计为 1,759 万平方公里（679 万平方英里），是有记录以来第三低的最大面积。
The maps below show the average concentration of Antarctic sea ice for the month of September (left) and the following February (right) from 1990 to 2026. Opaque white areas indicate the highest concentrations, and dark blue areas are open water. The images include only areas where ice concentration was at least 15 percent, a threshold scientists commonly use to count an area as ice-covered in satellite data. Scientists refer to the total area of these regions as the “sea ice extent.”
下图显示了 1990 年至 2026 年 9 月（左）和次年 2 月（右）南极海冰的平均浓度。不透明的白色区域表示浓度最高，深蓝色区域是开放水域。这些图像仅包含冰浓度至少为 15% 的区域，这是科学家通常用来在卫星数据中计算某个区域被冰覆盖的阈值。科学家将这些区域的总面积称为“海冰范围”。
From 1979 until 2014, total Antarctic sea ice increased by about 1 percent per decade. Whether the increase was a sign of meaningful change is uncertain because ice extents vary considerably from year to year around Antarctica. For three consecutive years, from 2012 to 2014, satellites observed new record highs for winter sea ice extent. These highs occurred while Arctic ice was in steep decline.
从 1979 年到 2014 年，南极海冰总量每十年增加约 1%。这种增加是否是有意义的变化的迹象尚不确定，因为南极洲周围的冰面积每年都有很大变化。从2012年到2014年，卫星连续三年观测到冬季海冰范围再创新高。这些高点发生时北极冰层急剧减少。
The climb came to an end in 2015, and significant decreases in sea ice around Antarctica started to occur in 2016. There have since been years with small rebounds, but overall, Antarctic sea ice coverage has largely remained lower than normal. Both the record low minimum and record low maximum occurred in 2023. Scientists will continue to observe the area each year to find out if the decline is part of a long-term change or a statistical fluctuation.
爬升运动于 2015 年结束，南极洲周围的海冰在 2016 年开始显着减少。此后的几年里出现了小幅反弹，但总体而言，南极海冰覆盖范围基本上仍低于正常水平。历史最低最低值和最高纪录最低值都出现在 2023 年。科学家们将继续每年观察该地区，以查明这种下降是长期变化的一部分还是统计波动的一部分。
To determine sea ice extent, scientists rely on satellites with passive microwave sensors that measure the microwave energy Earth naturally emits. Sea ice emits more of this energy than open water, so it stands out in microwave images. Because microwaves pass through clouds, the satellites can observe sea ice regularly, regardless of weather.
为了确定海冰的范围，科学家依靠带有无源微波传感器的卫星来测量地球自然发射的微波能量。海冰比开放水域释放更多的能量，因此它在微波图像中脱颖而出。由于微波穿过云层，因此无论天气如何，卫星都可以定期观测海冰。
The record began in late 1978 with data collected by NASA’s Nimbus-7 , followed by Defense Meteorological Satellite Program (DMSP) satellites starting in 1987, and by NASA’s Aqua satellite between 2002 and 2011. In 2025, scientists began using observations from the Japan Aerospace Exploration Agency’s GCOM-W satellite .
该记录始于 1978 年底，由 NASA 的 Nimbus-7 收集数据，随后从 1987 年开始由国防气象卫星计划 (DMSP) 卫星收集，并在 2002 年至 2011 年间由 NASA 的 Aqua 卫星收集数据。2025 年，科学家开始使用日本宇宙航空研究开发机构的 GCOM-W 卫星的观测数据。
NASA Earth Observatory images by Michala Garrison, using data from the National Snow and Ice Data Center .
美国宇航局地球观测站的图像由 Michala Garrison 使用国家冰雪数据中心的数据拍摄。