北大西洋秋季“三极子”海温结构对冬季大气环流场的影响

The impact of the autumn Atlantic sea surface temperature three-pole structure on winter atmospheric circulation

利用NCEP再分析资料、Hadley中心的海表面温度(SST)资料等,从北大西洋秋季海表面温度异常(SSTA)变化入手,对其影响后期冬季大气环流场的机制进行了分析。研究结果如下:(1)北大西洋SST异常与大气环流异常之间存在着相互作用;(2)秋季北大西洋SSTA具有较好的持续性,"正负正"海温异常空间分布导致12月巴伦支海上空500hPa位势高度异常偏高;(3)异常环流形势对应的海表面风异常场(SSWA)通过阶段性风-蒸发-SST异常反馈机制(WES机制)利于海温异常分布的持续及对上空异常大气环流的反馈;(4)三极子海温结构中负异常海温自10月份开始有自西向东的移动,风作用下蒸发加大,伴随上升运动自欧洲西部爱尔兰群岛出现自西向东移动的降水正异常区,潜热释放有利于冬季巴伦支海上空的异常高压脊发展。研究表明,北大西洋秋季SSTA通过阶段性海气相互作用机制影响海洋温度分布和大气环流异常,对后期冬季中国东北部的气候变化产生影响。

Based on the National Center for Environmental Prediction（NCEP）reanalysis data,Hadley Sea Surface Temperature（SST）and so on,this thesis analysed the mechanism of the autumn Atlantic SSTA effecting on the winter high altitude circulation.The research results are as follows：（1）There is an interaction between North Atlantic SSTA and the atmospheric circulation anomaly;（2）The autumn Atlantic SSTA has good continuity.Due to the continuity of the autumn SSTA in North Atlantic,the＂positive-negative-positive（＋-＋）＂distribution of North Atlantic SSTA leads to larger December 500 hPa geopotential height over the Barents Sea;（3）Under the sea surface wind anomaly（SSWA）actions,the feedback mechanism and wind-evaporation-SSTA can benefit the‘＋-＋＇SSTA lasting and the feedback to atmospheric circulation anomaly;（4）The negative SSTA moves easterly from October to December,and the stronger evaporation,because of the same wind direction of the SSWA and background wind,produces stronger up-vertical movement.With the positive precipitation area moving easterly from Western Europe,the latent heat transport to the Barents Sea along with the southeast airflow in front of the low trough,promotes the development of the Ridge.Research shows the SSTA and atmospheric circulation anomaly can be affected by autumn Atlantic SSTA through the periodic air-sea interaction mechanism and the winter climate change in Northeast China produces a corresponding change.