南极海冰和陆架冰的时空变化动态

Variation Trends of the Antarctic Sea Ice and Shelf Ice

利用美国冰中心和雪冰中心提供的海冰资料和我国南极考察现场的海冰观测资料,对南极海冰的长期变化进行了研究.结果表明:20世纪70年代后期是多冰期;80年代是少冰期;90年代南极海冰属于上升趋势,后期偏多;区域性变化差别大,东南极海冰偏多,西南极海冰即南极半岛两侧特别是威德尔海(WeddellSea)区和别林斯高晋海(BellingshausenSea)的冰明显偏少.东南极和西南极海冰的变化趋势总是反相的.90年代后期普里兹湾的海冰明显偏多,南极大陆陆架冰外缘线总体没有明显的收缩,有崩解也有再生的自然变化现象.西南极威德尔海的龙尼冰架(RonneIceShelf)和罗斯海冰架(RossIceShelf)东部崩解和收缩趋势明显,东南极的冰架也有崩解和收缩,但没有西南极明显.陆架冰崩解向海洋输送的冰山对全球海平面升高有一定的影响.目前,南极冰盖断裂崩解形成的冰山,向海洋输入的水量可使全球海平面上升约14mm.南极海冰没有随着全球气候温暖化而明显减少,而是按照东南极和西南极反相的变化规律进行周期性的变化、调整和制约.

In this paper, sea ice data provided by the Ice and Snow Center, USA and field observed sea ice data with assimilation processed are used to study the dynamic variation and long-term change trend of the Antarctic sea ice. The study shows that there were a period of more ice in the late 1970s and a period of less ice in the 1980s; While in the 1990s the Antarctic sea ice was in a increasing period with more ice in its later stage. There was a large regional variation difference in the 1990s, more ice in the eastern Antarctica and obviously less ice in the west Antarctica, both sides of the Antarctic Peninsula, especially in Weddell Sea and Bellingshausen Sea. The sea ice variation trend in the eastern and western Antarctica is always in opposite phase. In the late 1990s, sea ice in Prydz Bay was obviously rich. Along the outer periphery line of sea ice of the Antarctic continent shelf, on the wholly, there was no any evident retreat, with normal collapse and renascence. While in the western Antarctica, Ronne Ice Shelf of Weddell Sea and eastern part of Ross Sea Ice Shelf, collapse and retreat trend was evident. Collapse and retreat of ice shelf in the eastern Antarctica also occurred, but not as evident as in the western Antarctica. Iceberg from shelf ice collapse to ocean gives a certain impact on the global sea level rising. In a short word, the Antarctic sea ice had not obviously decreasing with global climate warming, but a normal periodical changing, with adjusting and restricting due to opposite phase variation in the eastern and western Antarctica.