赤道外北太平洋冬夏海温场的EOF分析  

EOF analysis on sea temperature field in the Extratropical North Pacific

作　　者：路凯程[1,2] 廖前锋[3] 张铭[2] 

机构地区：[1]中国人民解放军39506部队82分队 [2]中国人民解放军理工大学气象学院大气环流与短期气候预测实验室 [3]中国人民解放军理工大学训练部

出　　处：《海洋预报》2011年第5期50-60,共11页Marine Forecasts

基　　金：国家"973"项目-北太平洋副热带环流变异对大气强迫的反馈作用(2007CB411805)

摘　　要：利用较高分辨率的SODA资料,对赤道外北太平洋海洋上层各层的海温,特别是对中纬度北太平洋海温明显异常的海域(其被定义为关键区)做了海温的EOF分析,得到以下结论:北太平洋第一模态空间场上,冬、夏在中纬度北太平洋中西部均有较强正值带出现。在关键区第一模态空间场上,冬、夏两季近表层在日本本州岛的东、西面海域均分别有较强正值区,而次表层则仅存前者;这表明近表层海温(前者)受辐射、蒸发等影响明显,而次表层海温(后者)则其主要受流场垂直运动的影响,前者属海温的热力变化而后者则属海温的动力变化,两者性质不同。北太平洋和关键区的第一模态冬、夏海温变化的趋势均相近,两者在年尺度上均有持续性;两者的年际变化冬、夏均不明显,但均有明显的约20年的年代际变化;两者时间系数的演变均与太平洋年代际振荡(PDO)中的冷、暖位相期有较好的对应;这两个模态均可称为PDO模态。Based on the higher resolution SODA data, EOF diagnosis on temperature of upper seawater is made in extratropical North Pacific, especially in mid-latitude where SST anomalies obvious seas （which is called key area）. The results show that for the first mode of space field, there is positive high value zone at 40 °N Midwest of North Pacific in winter and summer. The anomalous trends of SST in winter and summer are same, which is sustained in year-scale. There are no obvious interannual variations between the two seasons, but 20-year inter- decadal variations are significant, suggesting the impacts of North Pacific Decadal Oscillation （PDO） on the SST change. In the east and west sea region of the Honshu, there are strong positive anomalies in winter and summer near sea surface, while only the east region remains at sub-surface. It indicates that the ocean temperature of near-surface is significantly affected by solar radiation and evaporation, but the sub-surface temperature is mainly controlled by the vertical motion of flow field.

关 键 词：北太平洋 海温异常 EOF分析 PDO 

分 类 号：P732[天文地球—海洋科学]