北极喀拉海工程海冰冰情特征统计分析

Statistical analysis on the engineering sea ice regime in the Kara Sea in the Arctic

本文基于ICDC海冰密集度、冰厚及NSIDC冰速数据,分析了喀拉海工程海冰时空变化特征,并采用ECMWF大气强迫资料,进一步分析了影响喀拉海冰情的热力与动力因素。结果显示,喀拉海海冰冰情总体呈现由重变轻趋势;海冰时空变化显著,存在8个月的高密集度完全冰封期,冬季月份全海域冰厚高于60cm,夏季西南部冰厚低于20cm,冻结快,融化慢;油气代表点处冰厚频率分布呈双峰状,常冰向及强冰向以NW、NNW及SSE方向为主;冬季积温是决定融冻期海冰覆盖率特征和增长期冰厚指数的主要因素;自2005年起,喀拉海夏季几近无冰,经向风场与海冰覆盖率开始存在相关性。

Spatio-temporal variations of engineering sea ice in the Kara Sea and the correlations with thermodynamic and dynamic factors are analyzed based on sea ice concentration and ice thickness datasets from ICDC,ice velocity dataset from NSIDC and atmospheric forcing dataset from ECMWF.The ice regime in Kara Sea is generally showing a declining trend.The sea ice varies significantly both temporally and spatially.The Kara Sea freezes faster than melts and is usually fully covered by high-concentration ice during 8 months with exceeding 60 cm ice thickness in winter months and less than 20 cm in southwest in summer.At the representative point of oil and gas,the ice thickness frequency is bimodal distribution,and the prevailing and strong ice directions are mainly NW,NNW and SSE.The winter accumulated temperature can greatly determine ice coverage characteristics during melting period and ice thickness index during growth period.Since 2005 the Kara Sea has become ice-free in summer and correlations start to exist between the meridional wind field and summer ice coverage anomaly.