采用逐次滤波法分析了北太平洋海洋大气系统年代际振荡特征及其主要影响因子,探索太阳活动对于北太平洋海洋大气系统年代际变化的影响。结果表明,太阳活动是北太平洋海洋大气系统周期性年代际振荡的重要影响因子,具体反映在:1)北太平洋年代际涛动(PDO,Pacific Decadal Oscillation)存在与太阳活动密切相关的22年周期和11年周期,是PDO仅次于趋势项最重要的周期成分,其方差贡献率分别为20.9%和6.7%。研究发现北太平洋年代际涛动变化对于太阳活动的响应方式与太阳活动强弱程度有联系,太阳活动水平强时PDO与太阳磁场变化符号相同并且振荡幅度大;太阳活动水平弱时PDO与太阳磁场变化符号相反并且振荡幅度小。2)滤除持续下降趋势之后,北太平洋冬季阿留申低压活动区海平面气压(SLP,Sea Level Pressure)表现出与太阳磁场磁性指数(MI,Magnetic index)基本反相的周期性振荡,滤除22年周期之后11年周期也比较清楚,其方差贡献率分别为13.4%和1.1%。3)滤除持续升温趋势以后北太平洋100hPa冬季大气温度距平场表现出与太阳磁场磁性指数基本一致的周期性振荡,滤除22年周期之后11年周期也比较清楚,其方差贡献率分别为15.1%和1.1%。研究结果说明,在太阳活动对于大气温度场的影响过程中,黑子磁场磁性变化是决定性的,即决定了温度变化符号,MI绝对值的变化即太阳磁场强度变化影响其量变。
The decadal oscillation in the ocean-atmosphere system in North Pacific and main factors were studied with stepwise filtration. Results show that it is the solar activity that triggers the oscillation, which gain supports from: 1) the Pacific Decadal Oscillation (PDO) had 22-year and 11-year periods, which matches those of the solar activity. The two periods are the second important components after the trend term, which contributed 20.9% and 6.7% respectively to the oscillation. The PDO variation is related to the scale of the solar activity: the stronger the solar activity, the larger the oscillation amplitude that in-phase with solar magnetic field variation, or vice versa, weak and out-of-phase. 2) After removing the descending trend, the sea lever pressure (SLP) in wintertime over the Aleutian Low area shows a periodic oscillation in anti-phase against that of the magnetic index (MI) of solar magnetic field. The 11-year period is obvious after the 22-year-period filtrated. The two periods accounted for 13.4% and 1.1% contribution to the variance, respectively. 3) After removing the ascending trend, the atmospheric temperature at 100 hPa in North Pacific is largely in phase of that of MI that shows a clear 11-year period once the 22-year period is cleared, and contributed 15.1% and 1.4%, respectively. Therefore, the solar activity affect the atmospheric temperature via magnetism change. The variation in absolute MI value determines the temperature.