Dynamics of the Arctic Oscillation and the Process of the Low-Frequency Variability

近年来，伴随着异常天气和全球变化问题，北极涛动越来越受到人们的关注。2006年第一年，2006年7月7日至8日在筑波大学举办了关于北极涛动研究的第一期讲习班。约30名与会者齐聚一堂，介绍最新的科学成果，并就这一主题进行讨论。首席调查员于2007年2月19日至20日在阿拉斯加费尔班克斯大学组织了第七届全球变化：与北极的联系国际会议(GCCA-7)，并介绍了北极涛动研究的审查情况。北极涛动研究第二期讲习班于2007年3月2日至3日在筑波大学举行。约40名与会者齐聚一堂，介绍最新的科学成果，并就这一主题进行讨论。2007年第二年，珠子调查员在2007年日本地球科学联合会会议期间组织了第一次北极科学联合会会议wi…更多的是关于北极涛动的专题。联盟会议将于2008年升级为常会。北极涛动研究的贡献被总结为2007年12月出版的《日本气象学会杂志》特别版。在特别版中，发表了12篇关于北极涛动主题的参考文献。根据这些论文的总结，我们得出结论：北极涛动可以理解为全球大气的一种动力奇异本征模。奇异本征模具有零本征值的独特性质，其结构与北极涛动相同，因此可以对任意准定常正压强迫作出共振响应。然而，太平洋和大西洋地区风暴路径的准稳定强迫是独立的，幅度很大，因此北极涛动似乎是EOF分析的统计产物，只承认大西洋地区的北大西洋涛动和太平洋地区的北大西洋涛动和太平洋北大西洋涛动的遥相关。较少

The Arctic Oscillation draws increasingly more attention in recent years in association with abnormal weather and global change problems. In the first year of 2006, the first workshop on the Arctic Oscillation Study was held during 7-8 July 2006 at the University of Tsukuba. About 30 participants gathered to present the latest scientific results and to discuss on the subject. The head investigator organized the 7th International Conference of the Global Change: Connection to the Arctic (GCCA-7) at the University of Alaska Fairbanks for 19-20 February 2007 and presented the review of the Arctic Oscillation study. The second workshop on the Arctic Oscillation Study was held during 2-3 March 2007 at the University of Tsukuba. About 40 participants gathered to present the latest scientific results and to discuss on the subject. In the second year of 2007, the bead investigator organized the first union session of the Sciences in the Arctic during the Japan Geosciences Union Meeting 2007 wi … More th a special topic of the Arctic Oscillation. The union session is upgraded to the regular session in 2008. The contributions from the Arctic Oscillation Studies were summarized as the Special Edition of the Journal of the Meteorological Society of Japan in December 2007 issue. In the Special Edition, 12 refereed papers on the subject of the Arctic Oscillation were published.According to the summary of these papers, we have reached to the conclusion that the Arctic Oscillation can be understood as a dynamical singular eigenmode of the global atmosphere. The singular eigenmode has a unique property of zero eigenvalue with a structure identical to the Arctic Oscillation so that it can respond resonantly to arbitrary quasi-steady barotropic forcing. However, the quasi-steady forcing from the storm tracks at the Pacific and Atlantic sectors acts independently with large amplitudes, so the Arctic Oscillation apperas as if it is a statistical artifact of the EOF analysis, recognizing only the teleconnections of NAO in the Atlantic sector and PNA in the Pacific sector. Less