极地研究

极地研究 ›› 2012, Vol. 24 ›› Issue (1): 35-46.DOI: 10.3724/SP.J.1084.2012.00035

• 研究论文 • 上一篇    下一篇

北极海冰快速减少期间加拿大海盆上层海洋夏季淡水含量变化

郭桂军1,史久新1,2,赵进平1,2,矫玉田1,2,徐栋1   

  1. 1中国海洋大学海洋环境学院
    2    教育部物理海洋学重点实验室
  • 收稿日期:2011-05-30 修回日期:2011-07-22 出版日期:2012-03-30 发布日期:2012-03-30
  • 通讯作者: 郭桂军
  • 基金资助:

    北极环极边界流的结构及其对气候变化贡献的研究;北冰洋盐跃层的演变及其热力学效应研究

Summer freshwater content variability of the upper ocean in Canada Basin during recent sea ice rapid decline

  • Received:2011-05-30 Revised:2011-07-22 Online:2012-03-30 Published:2012-03-30
  • Contact: Gui-Jun GUO

PDF (PC)

1629

被引次数

6

摘要：

北极海冰近年来快速减少，北冰洋淡水含量也出现了急剧变化。加拿大海盆作为北冰洋淡水的主要存储区域，研究其淡水含量变化对于认识北冰洋淡水收支有重要意义。本文根据2003年、2008年中国北极考察以及2004年至2007年的加拿大考察数据进行计算，发现除2006年以外，夏季加拿大海盆淡水含量在此期间每年增加1m以上厚度。增加主要发生在冬季白令海水以上的上层海水中，而在此之下，淡水含量维持在3m左右，没有显著年际差异。在2006年，加拿大海盆西部上层淡水含量略微减少，但东部和北部海域淡水含量仍略有增加。与2003年相比，2008年加拿大海盆中心海区淡水含量增加量最高可达7m。分析表明，近年来的海冰减退对加拿大海盆上层淡水含量的增加起着重要作用，北极涛动(AO)正负相位变化也是控制其淡水含量变化的一个重要因素。而降水、径流以及白令海峡入流水的变化对加拿大海盆淡水含量变化影响较小。

关键词: 加拿大海盆, 淡水含量变化, 海冰, 北极涛动

Abstract:

With sea ice extent decreasing significantly in recent years, freshwater content(FWC) in the Arctic Ocean has accordingly shown rapid changes. Research on freshwater content variability in Canada Basin, the main area storing fresh water, has a profound significance for understanding the input-output fresh water in the Arctic Ocean. Based on the data from Chinese National Arctic Research Expedition in 2003 and 2008, and the data from expeditions aboard the Canadian ship LSSL from the year 2004 to 2007, the FWC in Canada Basin was calculated. The results showed that the upper ocean in the Canada Basin had been becoming fresher continuously from 2003 to 2008, except for that of 2006. The FWC increased at a rate of more than 1m/yr, and the maximum increase was in the central Canada Basin, by approximately 7m, compared between 2008 and 2003. Variability of FWC was almost limited to the layer above the Winter Bering Sea Water (wBSW), below which the FWC was maintained around 3m during this study period. The main contributors to the FWC increase were generally considered as precipitation larger than evaporation, the changes of runoff, Pacific water inflow through Bering Strait, sea ice extent, and the Arctic Oscillation. However, as we determined that the previous three contributors did not have apparent impact on FWC changes, this paper focused on the analysis of the later two factors, which were the key contributors to the freshwater content variability.

Key words: Canada Basin, Freshwater content, sea ice, Arctic Oscillation(AO)

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