大气科学2011，Vol.35Issue(2)：326-338,13.
北大西洋涛动指数变化与北半球冬季阻塞活动
The Effect of the Variation of the North Atlantic Oscillation on Winter Blocking Activities in the Northern Hemisphere
摘要
Abstract
The linear regression analysis shows that there is a significant correlation between the North Atlantic Oscillation (NAO) and the variation of blocking frequency and intensity in the Atlantic Ocean, Europe, and the Ural Mountains. During the negative NAO phase, the blocking activities are more frequent and stronger in the Atlantic region. In the positive NAO phase, the blocking activities in the Atlantic region and their frequency diminish, which enhance in Continental Europe, and at the same time the blocking activities reduce markedly in the Ural Mountains. The increase and decrease of positive NAO index correspond to different variations of the blocking activities in the Atlantic Ocean and Europe. The local distribution of blocking activities' frequency demonstrates that during the increasing phase of the positive NAO index the blocking activities in the Atlantic Ocean are significantly restrained,which enhance evidently in Continental Europe, and their center shifts to the Continent. But in the weakening stage of the positive NAO index, the center of blocking activities shifts westward to the Atlantic Ocean. The annual changes in the regional blocking events show that the blocking situations in the Atlantic and the Urals region have a downward trend during the enhancing phase of the NAO index, which increase in Europe; in the weakening phase of the NAO index, the Atlantic blocking cases present a weak uptrend, which trend downwards in Europe and the Ural region. The strength and position of mid-latitude eddy play an important role in the NAO phase variations. The eastward strengthening of the Atlantic storm track is beneficial to NAO tending to positive phase, corresponding to increasing in blocking frequency in Continental Europe, but further strengthening can increase blocking activities in the Atlantic Ocean.关键词
北大西洋涛动指数/阻塞活动特征/变化趋势Key words
North Atlantic Oscillation index/ blocking activities/ variation and trend分类
天文与地球科学引用本文复制引用
柴晶品,刁一娜..北大西洋涛动指数变化与北半球冬季阻塞活动[J].大气科学,2011,35(2):326-338,13.基金项目
国家自然科学基金资助项目40905030、10735030 （）
