Abstract:

Changes in the extent of Southern Ocean sea ice caused by global climate change have caused widespread concern. Based on nearly 35 years’ data of the temporal and spatial variations of sea ice extent, the Pearson correlation and cluster analysis techniques were used to explore its relationship with the Multivariate ENSO  Index (MEI), Oceanic Nino Index (ONI), and the area of the ozone hole. A small increase 1.1% （± 0.6%) was found in the extent of sea ice in the Southern Ocean, and the sea ice of the Indian Ocean was found to have grown fastest during the past 5 years. The multiyear trend of sea ice in the Bellingshausen/Amundsen seas was found to be negative in January–June, similar to the trend in the Weddell Sea in June–September and in November. Different relationships were found between the extent of sea ice in five sea areas and climate change factors. For example, the ONI mainly influences the Bellingshausen/Amundsen, Weddell, and Ross seas and the Indian Ocean; the MEI influences the Indian Ocean and the Ross Sea, and the ozone hole influences the Ross and Weddell seas. Different degrees of lag were found between sea ice extent and climate change.