Possible influence of stratospheric circulation on January surface air temperature over China

In terms of monthly NCEP/NCAR and 160 site temperature data from NCC (National Climate Center), the main modes of January surface air temperature in 1979-2008 over China and possible mechanism of typical cold/warm episodes are investigated. Results show that the first mode for January temperature is characterized by consist variation in China, which is closely related to circulation anomalies in stratosphere. From the wave source over East Asian in stratosphere wave fluxes propagate downward and westward, and in upper troposphere over North Atlantic there is a remarkable convergent area of wave flux leading to the ridge enhanced with stronger heat transforming to the North and front zone moving to more northerly. Thereby jet stream becomes strong and expands to East Atlantic with positive (negative) NAO anomaly pattern and higher pressure occurs south to Baikal indicating stronger (weaker) than normal cold air, which is helpful for lower (higher) temperature appearing over China