北极巴伦支海海冰多年变化特征研究

本文采用2003～2016年SSMI海冰密集度和NCEP气温、风场等数据,通过计算海冰覆盖率、增长期长度、冬季负积温和风拖曳力等参数,分析了巴伦支海海冰的变化特征及其与热力、动力影响因素之间的联系。结果显示,因西南部存在常年无冰区,巴伦支海14a平均的海冰覆盖率低于50%;覆盖率总体呈现下降趋势,冰情呈现"重—中等—轻"的变化过程,2012年后甚至出现夏季无冰的情况;增长期长度先增后减,起止时刻均有推迟;冬季负积温是影响巴伦支海冰情轻重的重要因素,与年平均海冰覆盖率距平和最大覆盖率的相关系数分别为-0.90和-0.89;风拖曳力的改变可在短期内引起海冰覆盖率急剧变化,是海冰边缘区产生流冰的主要原因,易对油气资源开发的海洋平台产生危害。

Study on Multiyear Variations in Sea Ice in the Barents Sea

Multiyear variations in the sea ice in the Barents Sea and its correlations with thermodynamic and dynamic factors are analyzed by calculating ice coverage, ice growth period, winter negative accumulated temperature and wind drag force based on SSMI sea ice concentration and NCEP air temperature, wind velocity from 2003 to 2016. Results show that the multiyear averaged ice coverage is less than 50% due to a permanent ice-free area in the southeast Barents Sea. The coverage is declining during these years, with. a trend of heavy-medium-light’ ice conditions. There is even no ice in summer after 2012. The increasing period of sea ice became longer and then shorter during 14 years, and its starting and ending date both delayed. The correlations between winter accumulated temperature and annual mean ice coverage anomaly, maximum coverage are-0.90 and-0.89 respectively, which indicates that accumulated temperature is one of important influence factors of ice condition in Barents Sea. The variations of wind drag force can cause sharp change of ice coverage in short time, resulting in drift ice in the marginal ice zones which might be harmful to offshore platform.