[A-AS06] 成層圏・対流圏過程とその気候への影響

[AAS06-05] 2019-2020年北半球冬季の成層圏周極渦強化状態とその対流圏への影響

*野口 峻佑^1,2、小寺 邦彦²、水田 亮²、行本 誠史² (1.国立研究開発法人 海洋研究開発機構、2.気象庁 気象研究所)

キーワード：成層圏-対流圏結合、北極オゾン層破壊、北極振動/北半球環状モード

Tropospheric responses to the remarkably strong stratospheric polar vortex condition in 2019-2020 Arctic winter and spring have been investigated by conducting a series of ensemble forecast experiments. In particular, by conducting ensemble "nudged" integrations, whose stratospheric circulation is relaxed toward a reanalysis, and comparing them with reference ensemble integrations, we deduce a significant effect of the stratosphere on the culmination of the anomalous circulation pattern characterized by a positive phase of the Arctic Oscillation. Various factors that led to the formation of anomalies in the stratosphere and troposphere during this extreme season will also be discussed through comparisons between the experiments and additional experiments.