世界最大冰山，没了

近日，南极冰山A23a完成末次崩解，主体部分仅剩35.2平方公里。从1986年脱离南极菲尔希纳冰架时的4170平方公里，到如今低于国际惯用的面积20平方海里（约68.6平方公里）冰山编号标准，这座曾经的世界最大冰山走完了40年生命历程。

从2022年末A23a加速漂流开始，我国风云气象卫星对其进行了持续监测。监测用了哪些“绝招”？下一座被持续监测的“巨无霸”冰山是谁？记者12日采访了中国气象局相关专家。

这是在南极威德尔海拍摄的冰山。图源：新华社

China's Fengyun meteorological satellites have documented the disintegration of what was once the world's largest iceberg, A23a, the China Meteorological Administration said.

The largest remaining fragment now measures only 11 kilometers in length, with its area reduced to 35.2 square kilometers, no longer meeting the criteria for classification as an iceberg, marking the end of its 40-year existence.

记录最大冰山生命晚期

A23a冰山长期搁浅于威德尔海，直到2020年前后因冰层融化才向北缓缓移动，2022年末移动开始加速。

Since late 2022, A23a accelerated its drift until it could no longer be tracked as an independent iceberg. Its final phase was comprehensively documented by Fengyun satellites.

国家卫星气象中心（国家空间天气监测预警中心）国际用户服务中心首席专家郑照军介绍，从2022年末开始，风云气象卫星监测到A23a的7个明显变化时段：威德尔海加速漂移阶段（2022年末至2024年初），卷入海洋涡旋滞留（2024年3月至12月），南乔治亚岛西南大陆架搁浅（2025年3月至5月），重新漂移并大规模崩解（2025年6月至8月），灾难性大幅解体（2025年9月），瘦身后向低纬度漂移并显著融化（2025年10月至2026年1月），连续三次末期崩解至编号注销（2026年2月至4月）。

A research team led by Zheng Zhaojun, chief expert at the National Satellite Meteorological Center's International User Service Center, used remote sensing data from Fengyun satellites to monitor A23a's trajectory, morphological changes and disintegration process over the years.

Monitoring showed that A23a, which had long been grounded in the Weddell Sea, began to detach from the seafloor due to melting ice around 2020, though it remained largely stationary.

It was not until late 2022 that significant movement was observed. In early 2023, A23a's area was 4,035 square kilometers, earning recognition by Guinness World Records as the world's largest iceberg at the time. It then began accelerating, leaving the Weddell Sea in 2024 and entering the Antarctic Circumpolar Current.

Between June and September 2025, the iceberg experienced several large-scale fractures during its northward drift, reducing its area from 3,536 square kilometers at the start of the year to about 1,400 square kilometers. By January 2026, further disintegration left the main body at just 503 square kilometers.

Subsequently, propelled by the Antarctic Circumpolar Current, A23a drifted rapidly, undergoing three more collapses in its final phase.

“目前我们正在以A23a为例，开展冰山崩解引发的海表生态变化研究。”国家卫星气象中心（国家空间天气监测预警中心）国际用户服务中心工程师陈一晖说，从2025年底起，A23a破碎冰区逐步出现“变绿”迹象，绿色羽流区不断发展变化，这与冰山融水导致海洋藻华爆发密不可分，我们正结合多源观测开展深层次的分析研究。

Since late 2025, satellite imagery has shown a gradual "greening" of waters in the fragmented ice zone around A23a, with green plumes expanding and shifting over time.

The discoloration of the sea surface is closely linked to phytoplankton blooms triggered by the influx of meltwater. The team is conducting further analysis to better understand the ecological effects associated with iceberg melt in polar regions.

风云卫星监测的A23a冰山漂移路径（圆点为冰山位置，时间与右侧标注对应；图底色和箭头表示洋流）。图源：中国气象局

监测南极冰山有“绝招”

堪称冰山监测“侦察兵”的风云气象卫星，监测冰山时有不少“绝招”。

“风云气象卫星擅长回答‘冰山在哪里、有多大、往哪走’的宏观问题，也能监测‘冰山表面是否有裂隙、哪里融化、大块裂解还是层层崩解’的中观与形态学问题。”郑照军说。

目前，风云三号D、F、H三颗卫星的250米中分辨率光谱成像仪是冰山监测主力，其多光谱观测能较好地区分显示云和冰雪，且一天至少有12次过极区观测；风云三号E星在极昼期间可提供辅助观测。风云三号风场测量雷达和微波成像仪，也能全天候、透过云层监测大型冰山。

“风云三号全球海冰、海温、洋面风以及海洋水色监测产品，有助于协同分析热力场、动力场变化对冰山漂移和融化崩解的影响，对冰山产生的生态环境变化也具有监测能力。”郑照军说。

风云气象卫星监测的A23a冰山末次崩塌真彩色监测图。图源：中国气象局

下一个监测目标——A81冰山

谈及风云气象卫星持续监测A23a的科学意义，陈一晖说，风云气象卫星对A23a的连续、自主监测，为极地与全球气候变化研究发挥作用。A23a加速漂移和快速崩解，成为南大洋增温的敏感指示器，其淡水释放与面积变化数据，为全球温盐环流模拟提供关键约束。

郑照军表示，下一个监测目标是已处于南极威德尔海北部、面积1400多平方公里的A81冰山，预计今年底或明年初这座“巨无霸”冰山会进入南极绕极流，开启深度融化和崩解之旅。

记者：赵伊梦

来源：新华社微信公众号 中国日报网

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