世界最大冰山，沒了

近日，南極冰山A23a完成末次崩解，主體部分僅剩35.2平方公里。從1986年脫離南極菲爾希納冰架時的4170平方公里，到如今低于國際慣用的面積20平方海里（約68.6平方公里）冰山編號標(biāo)準(zhǔn)，這座曾經(jīng)的世界最大冰山走完了40年生命歷程。

從2022年末A23a加速漂流開始，我國風(fēng)云氣象衛(wèi)星對其進(jìn)行了持續(xù)監(jiān)測。監(jiān)測用了哪些“絕招”？下一座被持續(xù)監(jiān)測的“巨無霸”冰山是誰？記者12日采訪了中國氣象局相關(guān)專家。

這是在南極威德爾海拍攝的冰山。圖源：新華社

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.

記錄最大冰山生命晚期

A23a冰山長期擱淺于威德爾海，直到2020年前后因冰層融化才向北緩緩移動，2022年末移動開始加速。

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.

國家衛(wèi)星氣象中心（國家空間天氣監(jiān)測預(yù)警中心）國際用戶服務(wù)中心首席專家鄭照軍介紹，從2022年末開始，風(fēng)云氣象衛(wèi)星監(jiān)測到A23a的7個明顯變化時段：威德爾海加速漂移階段（2022年末至2024年初），卷入海洋渦旋滯留（2024年3月至12月），南喬治亞島西南大陸架擱淺（2025年3月至5月），重新漂移并大規(guī)模崩解（2025年6月至8月），災(zāi)難性大幅解體（2025年9月），瘦身后向低緯度漂移并顯著融化（2025年10月至2026年1月），連續(xù)三次末期崩解至編號注銷（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.

“目前我們正在以A23a為例，開展冰山崩解引發(fā)的海表生態(tài)變化研究。”國家衛(wèi)星氣象中心（國家空間天氣監(jiān)測預(yù)警中心）國際用戶服務(wù)中心工程師陳一暉說，從2025年底起，A23a破碎冰區(qū)逐步出現(xiàn)“變綠”跡象，綠色羽流區(qū)不斷發(fā)展變化，這與冰山融水導(dǎo)致海洋藻華爆發(fā)密不可分，我們正結(jié)合多源觀測開展深層次的分析研究。

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.

風(fēng)云衛(wèi)星監(jiān)測的A23a冰山漂移路徑（圓點(diǎn)為冰山位置，時間與右側(cè)標(biāo)注對應(yīng)；圖底色和箭頭表示洋流）。圖源：中國氣象局

監(jiān)測南極冰山有“絕招”

堪稱冰山監(jiān)測“偵察兵”的風(fēng)云氣象衛(wèi)星，監(jiān)測冰山時有不少“絕招”。

“風(fēng)云氣象衛(wèi)星擅長回答‘冰山在哪里、有多大、往哪走’的宏觀問題，也能監(jiān)測‘冰山表面是否有裂隙、哪里融化、大塊裂解還是層層崩解’的中觀與形態(tài)學(xué)問題。”鄭照軍說。

目前，風(fēng)云三號D、F、H三顆衛(wèi)星的250米中分辨率光譜成像儀是冰山監(jiān)測主力，其多光譜觀測能較好地區(qū)分顯示云和冰雪，且一天至少有12次過極區(qū)觀測；風(fēng)云三號E星在極晝期間可提供輔助觀測。風(fēng)云三號風(fēng)場測量雷達(dá)和微波成像儀，也能全天候、透過云層監(jiān)測大型冰山。

“風(fēng)云三號全球海冰、海溫、洋面風(fēng)以及海洋水色監(jiān)測產(chǎn)品，有助于協(xié)同分析熱力場、動力場變化對冰山漂移和融化崩解的影響，對冰山產(chǎn)生的生態(tài)環(huán)境變化也具有監(jiān)測能力。”鄭照軍說。

風(fēng)云氣象衛(wèi)星監(jiān)測的A23a冰山末次崩塌真彩色監(jiān)測圖。圖源：中國氣象局

下一個監(jiān)測目標(biāo)——A81冰山

談及風(fēng)云氣象衛(wèi)星持續(xù)監(jiān)測A23a的科學(xué)意義，陳一暉說，風(fēng)云氣象衛(wèi)星對A23a的連續(xù)、自主監(jiān)測，為極地與全球氣候變化研究發(fā)揮作用。A23a加速漂移和快速崩解，成為南大洋增溫的敏感指示器，其淡水釋放與面積變化數(shù)據(jù)，為全球溫鹽環(huán)流模擬提供關(guān)鍵約束。

鄭照軍表示，下一個監(jiān)測目標(biāo)是已處于南極威德爾海北部、面積1400多平方公里的A81冰山，預(yù)計(jì)今年底或明年初這座“巨無霸”冰山會進(jìn)入南極繞極流，開啟深度融化和崩解之旅。

記者：趙伊夢

來源：新華社微信公眾號 中國日報(bào)網(wǎng)

跟著China Daily

精讀英語新聞

“無痛”學(xué)英語，每天20分鐘就夠！