乌拉尔阻塞与巴伦支-喀拉海海冰的季节特征及其相关关系

The Seasonal Characteristics and Correlativity Between Ural Blocking and Barents-Kara Sea Ice

本文采用经验正交函数分析、线性回归、相关性分析等方法对1982—2017年乌拉尔阻塞(UB)与巴伦支-喀拉海(BKS)海冰季节特征及其相关关系进行分析发现,UB活动频率与BKS海冰密集度均有较强的季节性周期变化,且不同季节BKS海冰与UB相关性不同。进一步对秋季UB与冬季BKS海冰的相关关系分析发现:秋季UB频率在BKS及其周边区域增多的年份里,秋季到冬季结冰期内,局地BKS海域500hPa位势高度持续增加、低层大气温度持续升高;同时,秋季BKS海域海表面温度异常增暖持续至冬季。上述海洋、大气条件不利于结冰期BKS海冰的冻结,因此这些年份里冬季BKS海冰密集度减少。此外,秋季BKS海冰减少也伴随着冬季UB高纬度频率增加。

This paper analyzes the seasonal characteristics and correlativity of Ural blocking(UB)and the Barents and Kara Seas(BKS)ice from 1982 to 2017 by using the methods of empirical orthogonal function(EOF)analysis,linear regression and correlation analysis.The results showed that both UB activity frequency and BKS sea ice concentration had strong seasonal cycle changes,and the correlation between UB and BKS sea ice was different in different seasons.Further analysis of the correlation between autumn UB and BKS sea ice in winter reveals:in the years when autumn UB frequency increases over the BKS and its surroundings,from autumn to winter,the geopotential height at 500 hPa in local BKS continued to increase significantly,and the low-level air temperature continued to rise;meanwhile,the sea surface temperature was abnormally warm up to winter.The above oceanic and atmospheric conditions are not conducive to the freeze-up of BKS sea ice,so the sea ice concentration of BKS in winter decreased in these years.In addition,the decrease of BKS sea ice in autumn was accompanied by the increase of UB frequency at high latitude in winter.