The Corresponding Tropospheric Environments during Downward-extending and Nondownward-extending Events of Stratospheric Northern Annular Mode Anomalies

Wenshou Tian1, Ruhua Zhang1, Jiankai Zhang1, Jinlong Huang1, Fei Xie2 and Mian Xu1, (1)Lanzhou University, Lanzhou, China, (2)Beijing Normal University, Beijing, China