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为定量分析北冰洋海冰密集度年际差异,提出并采用累积海冰密集度(ASIC)概念。利用SSMR/SSMI的分辨率为25 km的海冰密集度数据,分别研究了1979—2011年北极海冰在融冰期(4~9月)和结冰期(10月至翌年3月)的变化过程以及2个冰期内ASIC的区域差异。研究发现,在1979—1989年、1989—1999年和1999—2009年期间,融冰期海冰发生明显变化的范围都远远大于结冰期海冰发生明显变化的范围。1998—2010年,融冰期内发生加速融化的海区并没有都出现结冰期冰量减小的现象。在此期间融冰期ASIC减小,结冰期ASIC也减小的海域仅集中在楚克奇海、新地岛北部海域以及格陵兰岛东西海岸。融冰期ASIC减小,而结冰期ASIC无明显变化的海域包括波弗特海、东西伯利亚海、拉普捷夫海和喀拉海。这些区域与局地陆地径流侵入的海域重合。研究发现,在这些区域,融冰期ASIC减少是陆地径流增大加速海冰融化引起的。在结冰期,陆地径流加速海水结冰的作用消除融冰期海水吸收大量太阳辐射能后发生推迟结冰的现象,使得ASIC无明显变化。融冰期ASIC减小,而结冰期ASIC增大的区域只有白令海。研究结果证明累积海冰密集度能够去除海冰高频变化而只表现低频变化,能够描述海冰的年际变化特征。同时由于海冰变化与海洋中其他物理参数存在显著关系,变T的ASIC可以更加方便地描述次表层叶绿素最大值层深度的变化。
In order to quantitatively analyze the interannual variability of Arctic sea ice concentration, the concept of cumulative sea ice concentration (ASIC) was proposed and adopted. Based on the sea ice concentration data of SSMR / SSMI with a resolution of 25 km, the changes of Arctic sea ice during the ice melting period (from April to September) and the freezing period (from October to March next year) from 1979 to 2011 were studied respectively Process and regional differences in ASICs during 2 glacial periods. The study found that during 1979-1989, 1989-1999 and 1999-2009, the range of sea ice changes during the ice melting period was much larger than that during the ice period. In 1998-2010, there was not any decrease of ice volume during the ice-forming period in the sea areas that accelerated melting during the ice melting period. In the meantime, the melting-thawing ASIC was reduced and the area with reduced icing ASICs was only concentrated in the Chukchi Sea, the northern part of Novaya Zemlya and the east-west coast of Greenland. Ice melting ASIC decreases, while no significant changes in ice during ASIC ASICs include the Beaufort Sea, Eastern Siberia, Laptev Sea and the Kara Sea. These areas coincide with the intrusion of local land runoff. The study found that in these areas, the decrease of melting-thaw ASIC was caused by the increase of land runoff and acceleration of sea ice melting. In the icing period, land runoff accelerated the role of sea ice icing to eliminate the ice melting sea water absorb large amounts of solar radiation postponed the phenomenon of icing, making ASIC no significant change. Ice melting ASIC is reduced, while the ice period ASIC increases the area only the Bering Sea. The results show that the accumulation of sea ice concentration can remove high frequency changes of sea ice and show only low frequency changes, and can describe the interannual variability of sea ice. At the same time, the change of sea ice has significant relationship with other physical parameters in the oceans, so the ASIC with variable T can more conveniently describe the change of the depth of sub-surface chlorophyll maximum.