| 摘要: |
| 20世纪60年代， Namias(1969)就发现北太平洋海平面气压(SLP)存在10a以上长周期的变化，这种变化与北美冬季气温异常密切相关。70年代以后，又有人(White et al.，1972； Trenberth，1990； Trenberth et al.，1994)对上述变化作了进一步的验证，并指出1976年以后北太平洋的SLP异常偏低，即阿留申低压异常偏强。以阿留申低压为主要活动中心的大气年代际振荡被称为北太平洋涛动(NPDO)，它与北大西洋涛动(NAO)一起构成年代际气候变动最重要的观测依据，北太平洋年代际振荡的机制也引起了人们的广泛兴趣。作为大气运动的缓变下垫面强迫之一的海表面温度(SST)，它的异常变化对年际气候的显著影响已被公认(Wallace et al.，1981，1998)，由此推断，其对年代际时间尺度气候变化的影响可能也不可忽视。众所周知，SST年际变化最显著区位于赤道中东太平洋(如Nino 3区)，而与北太平洋年代际振荡显著相关的SST变化(时间变化和空间分布)又如何呢?作者就这一问题，分析了北太平洋大气环流年代际振荡的时、空变化特征，并揭示了与之相关的SST变化的时间变化和空间分布。 |
| 关键词: 北太平洋 年代际变化 海表面温度 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院海洋研究所调查研究报告第3888号。国家自然科学基金资助项目，49906003号。 |
|
| INTERDECADAL VARIABILITY OF ATMOSPHERIC CIRCULATION OVER THE NORTH PACIFIC AND ITS RELATED SST VARIATION |
|
Wu Aiming, Hu Dunxin, Bai Xuezhi
|
|
Institute of Oceanology, Chinese Academy of Sciences
|
| Abstract: |
| Based on the NCEP-reanalyzed atmospheric data and COADS SST data for the recent 50 years, interdecadal oscillation of the atmospheric circulation over the North Pacific Ocean in winter and its related temporal and spatial variations of SST were examined. The results indicate significant interdecadal variability of the atmospheric circulation over the North Pacific Ocean with principal periods of 16-22 years. Before 1977, PNA indices were basically negative but positive after 1977, a turning point year of interdecadal variability. The temporal change revealed by the first mode (EOF1 of the interdecadal component of the atmospheric height over the Pacific Ocean in winter, showed that 1977 was the only turning point in the recent 50 years, while the spatial distribution is of typical NPDO structure-before/after 1977 the atmospheric potential height over the North Pacific Ocean was higher/lower. SST changes associated with interdecadal oscillation of atmospheric circulation over the North Pacific Ocean in winter to large extent are the SST interdecadal components themselves, i.e. air-sea interaction possesses selectivity in time scale. |
| Key words: interdecadal variations,North Pacific Ocean,SST |
