北方涛动同北半球温带大气环流的遥相关(二)——季节变化

Teleconnections Between the Northern Oscillation and Extratropical Atmospheric Circulation of the Northern Hemisphere II: Seasonal Variations

在以前工作的基础上,本文进一步分析了各个季节北方涛动和与其相联系的北太平洋海温同北半球温带大气环流遥相关的特征,并与南方涛动和赤道太平洋海温的结果进行了比较,发现它们同北半球温带大气环流的遥相关,不仅具有很强的地区性,而且具有明显的季节变化。 冬季,北方涛动和北太平洋海温与PNA型相关非常明显,且比南方涛动和赤道太平洋海温的更密切。除PNA型外,北方涛动还同500hPa高度的亚洲-北美(ANA)流型有联系。 夏季,PNA遥相关型的表现仍然非常清楚,但位置较冬季偏酉和偏北,并在北美西海岸具有特殊的分叉现象。在东亚和太平洋地区,北方涛动的相关场呈EAP型;在太平洋-欧亚地区,南方涛动和赤道太平洋海温的相关场呈PEA型。这两个遥相关型都具有相当正压的垂直结构。 春季和秋季的相关场特征分别与冬季和夏季的类似。

On the basis of previous work, the seasonally in the associations of the Northern Oscillation ( NO) and its associated northern Pacific sea surface temperature (NPSST) with the extratropical atmospheric circulation of the Northern Hemisphere is analyzed. The results are compared with those of the Southern Oscillation (SO) and the equatorial Pacific sea surface temperature (EPSST). It is found that their teleconnections with the extratropical Northern Hemisphere atmospheric circulation are different in different regions and have obvious seasonal variations.