北极阿蒙森湾冬季冰下海水结构及对流混合研究  

A STUDY OF WATER PROPERTIES AND CONVECTION UNDER SEA ICE IN WINTER AMUNDSEN GULF

作　　者：李翔[1] 赵进平[1] 李涛[1] 李淑江[1] 

机构地区：[1]中国海洋大学,青岛266100

出　　处：《极地研究》2010年第4期404-414,共11页Chinese Journal of Polar Research

基　　金：国家自然科学基金重点项目(No.40631006);国际(地区)合作交流项目(No.40810220);教育部留学回国人员科研启动基金(教外司留[2009]1001)资助

摘　　要：使用加拿大环北极冰间开放水道研究计划从2007年11月至2008年1月底整个极夜期间对北极阿蒙森湾的考察数据,研究了没有太阳加热条件下冰下海水的对流混合。结果表明,冬季冰下海水结构以对流混合为主要形式,混合层的深度达到数米至数十米。发生对流混合时并没有出现静力不稳定性现象,对流混合层密度小于下层水体密度,此处的对流混合不同于前人的发现,它是由于卤汁的不连续排放造成的。混合层的温度与海水的冰点非常接近,由结冰导致的密度对流所形成。跃层以下海水的温度也在持续下降,文中认为是通过跃层与上混合层交换热量导致的。在冬季的前期,混合层的厚度与混合层的盐度有很好的对应性,但晚冬两者有明显差别,混合层厚度趋于减小。通过对三个位置接近站位的观测结果表现对流混合层的演化规律,体现了对流混合层在整个冬季温度持续降低、盐度持续升高的特征。The convection under sea ice in winter Amundsen Gulf without solar heating is studied. The data we used are from Circumpolar Flaw Leads System Study project （ CFL） during the time of polar night from November 2007 to the end of January 2008. It is shown that the vertical haline convection is the main character of the sea water in winter time in this region. The thick-ness of the mixed layer varies from meters to tens of meters. No static instability is found,i. e. the density of the water in mixed lyaer is lower than that of the water below. Unlike the convec-tion others studied,the convection we observed is caused by continual released haline parcel. The temperature of the water in the mixed layer is almost at the freezing point,which is the re-sult of the haline/density convection during the period of the ice formation. Below the mixed layer,there is a warm layer. But the temperature decreased with time during the observation period. We think,the main reason for it is the energy exchange with the water in mixed layer. According to the results,the salinity and thickness of the mixed layer coincide in early winter, while the thickness decreased in late winter with the salinity increasing. We also analyzed the temperature and salinity data from 3 stations which are coarsely at the same position and found that the salinity of the mixed layer increased and the temperature of the warm layer decreased during the observation period.

关 键 词：对流混合 混合层 结冰析盐 温盐结构 北冰洋 阿蒙森湾 

分 类 号：P731.2[天文地球—海洋科学]