Abstract:

Using the NCEP/NCAR reanalysis data, Arctic Oscillation (AO) index series and monthly temperature at 160 weather stations in China, variation characteristics of winter air temperature and AO index series as well as both relationships from 1951 to 2007 were analyzed. The results show that there is a positive correlation relationship between winter air temperature and AO indexes in the eastern China. Winter air temperature index and Arctic Oscillation index both increase gradually. Their annual and inter-decadal variations are significant and both have a 18 years cycle. According to the partial correlation coefficient, effects of the Siberia high on winter air temperature in the eastern China are significant on annual scale, while the AO index has not a significant correlation with winter air temperature; effects of AO on winter air temperature are more significant than that of the Siberia high on interdecadal scale. Winter air temperature and AO index in the eastern China are high when the East Asian trough is weak, and vice versa. On inter-annual scale, the East Asian though has significantly effect on inter-annual variations of winter air temperature of Eastern China, while the correlation between AO and winter air temperature is not significant; on interdecadal scale, effects of AO index and the East Asian though on winter air temperature changes in the Eastern China are significant.

Key words:  Arctic Oscillation (AO), Winter air temperature, The Siberia high, The East Asian though