近百年全球平均地面气温准周期信号及其长期演变特征的分析

应用奇异谱分析(SSA)方法,对全球及南北半球近100多年(1856～1997年)逐月地面气温距平序列的年际变化准周期性进行诊断分析,结果表明,全球平均气温序列中以准5～6年和准4年周期振荡最显著,其次是准两年周期振荡.各种准周期振荡年代际演变特征及其变率的阶段性,不但表现在振幅上,而且其波数亦很明显.上述特征在全球、南北半球都各有明显的差异.奇异交叉谱分析(SCSA)表明,全球平均地面气温的年际振荡与气候系统中其他各子系统所隐含的准周期信号具有各种耦合关系,尤其表现在与Nino区海温或南方涛动指数中的准周期信号的耦合关系上.

Quasi-Periodic Signals and Its Features of Long-Term Change for Global Surface Temperatures over the Past Recent 100 Years

The quasi-periodicities of inter-annual variations for the inter-monthly surface air tem- perature anomaly series are diagnosed over the global, southern and northern hemispheres over the past more than 100 years (l856~ l997) by using singular spectrum analysis (SSA). The results show that there exist three dominant time scales with period ranges of 5~ 6 years, around 4 years and quasi-bien- nial oscillations in the global and both hemisphere temperature series. The first two period oscillations are the most prominent. The inter-decadal variations and the variability phase of the various quasi-pe- riod oscillations are displayed in amplitude and wavenumbers as well. The above-mentioned features are obviously different in the global and both hemisphere temperature series. Singular cross spectrum analysis (SCSA) shows that there exist various couple oscillations between the inter-annual oscillations of the global air temperature series and the quasi-period signals which other sub-climate systems hint, especially the couple oscillations between the inter-annual oscillations of the global temperature and the quasi-periods signals of the sea surface temperature (SST) or South Oscillation Index (SOI).