Characterization of 21st Century winter North Atlantic Oscillations and Winter Storm Track in North Hemisphere based on ECHAM5

ZHANG Meng; CHEN Xueen

Abstract：Based on the output of atmospheric model ECHAM5,the characteristics in the future 21st st century winter north Atlantic oscillations (NAO) appeared in three styles,for three scenarios (RCP2.6,RCP4.5 and RCP8.5,) of Winter North Atlantic Oscillation (NAO) and wWinter sStorm tTracks (WST) in the Nnorth hHemisphere were characterizedhave been studied.For all the styles of NOA,In the three scenarios,all NAO indices showed a cycle in a length of 9 to 14 years,and the intensity ies of WST hadve a growth trend with while their centers always moved to either northeast or southwest always.The results of cComposite analysis indicated that,the responses of WST responded to the shifting of NAO phrase differentially among three styles greatly for different scenarios.For the years when of weak NAO was weak,the area and intensity of the Pacific WST presented negatively anomaly,and the position keept s away from Eurasia in for RCP2.6.In contrast,,while the area of Atlantic WST was shows positively anomaly.For RCP4.5,the areas of both two WSTs increased in during NAO negative NAO phrase.In addition,the Atlantic WST strengthened with its s and its center located close to America.For RCP8.5 in during the same NAO phrase,both two WSTs intensifiedy.Meanwhile,the area of the Pacific WST rose with ises and its position keept s away from Eurasia.