不同平均强度热盐环流的年代际波动特征

基于美国国家大气研究中心的CCSM3(community climate system model version 3)模式，对淡水扰动试验下不同平均强度热盐环流(thermohline circulation，THC)的年代际波动特征及北大西洋气候响应特征进行研究。结果表明，百年以上尺度的THC变化对其年代际尺度波动产生显著影响，高平均强度下THC的年代际波动周期更长、更显著。对不同平均强度下北大西洋海、气要素与THC在年代际尺度上的相关分布进行分析，发现在高平均强度下，THC与海表温度(sea surface temperature，SST)的相关呈现为经向三核型分布，与海平面气压(sea lever pressure，SLP)的相关呈现为类NAO(North Atlantic oscillation)分布，而在低平均强度下，则不存在这2种模态分布；同时，在不同平均强度下，THC与各要素间的相关程度也不同，高平均强度下相关程度更高。

Interdecadal characteristics of thermohaline circulation with different mean intensities

The CCSM3(community climate system model version 3) model developed by the National Center for Atmospheric Research was used to study the interdecadal characteristics of thermohaline circulation(THC) in the freshwater disturbance experiments with different mean THC intensities, and the influences on North Atlantic climate. Results show that THC interdecadal fluctuation characteristics have significant differences in the experiments with different THC intensities.The impact of THC changes on more than 100 years scale on its interdecadal fluctuations is significant.In high average intensity,THC interdecadal fluctuation is longer and more significant.The interannual responses of SST(sea surface temperature) and SLP(sea lever pressure) to different THC intensities in North Atlantic are obviously different.In the high average intensity,the dominant correlation mode between North Atlantic SST and THC index exhibits a meridional tripole pattern,and the dominant correlation mode between North Atlantic SLP and THC index does a NAO(North Atlantic Oscillation) like pattern,but the two modes do not exit in the low average intensity.In high average intensity,the correlation between THC and the various elements is more significant.