Abstract:On the basis of monthly Arctic Oscillation (AO) data from NOAA (Climate Prediction Center, National Oceanic and Atmospheric Administration) and daily reanalysis data from NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research ) from 1986 to 2017, by using regression and synthetic analysis, the temporal evolution characteristics of AO and the North Pacific storm track, the relations between AO index and storm track index (including intensity, longitude, latitude index), and the possible physical mechanism of AO anomalies on the storm track are studied. The results are as follows. 1) The longitude index of the storm track has significant positive correlation with the latitude index of the storm track, and they both have the feature of synchronous change, but they both have nonsignificant negative correlation with the intensity index of the storm track. The correlation between AO index and the intensity of the North Pacific storm track is significantly positive. The correlation between AO index and the longitude/latitude of the storm track is positive, but not significant. 2) Further analysis indicates that, in the years when AO is in strong positive/negative phase, the synopticscale filtering variance becomes stronger/weaker, the East Asia major trough becomes weaker/stronger at the level of 500 hPa, the jet stream moves northward/southward and becomes stronger/weaker, the disturbance kinetic energy becomes stronger/weaker, and the baroclinicity becomes stronger/weaker in the areas of the North Pacific storm track. The possible influence mechanism is that the anomalous changes of AO affect the East Asia major trough, change the intensity of westerly jet stream and the baroclinicity, and then exert an effect on the storm track.