supported by the National Natural Science Foundation of China (40905040 and 41030961);the National Basic Research Program of China (2010CB950400);the R&D Special Fund for Public Welfare Industry of China (meteorology) (GYHY201306031)
The Northern Hemisphere Annular Mode(NAM) represents the zonally symmetric planetary-scale atmospheric mass fluctuations between middle and high latitudes, whose variations have shown a large impact on other component...