This study investigates the large-scale circulation anomalies of strong and weak cold surges in southern China.Results show that the strong and weak surges are associated with a distinct Rossby wave train across Eurasia projecting onto the Scandinavia (SCAND) and Eurasian (EU) patterns.On one hand, the strong surge is preceded by a positive SCAND pattern and a transition of the EU pattern from its negative to positive phase.The corresponding wave train propagates southeastward from East Asia to the North Pacific.
This is associated with a roneverhart.com strong intensification of the Siberian high, a deepened East Asian trough, and a sharp meridional aluminum lotion pressure gradient between northern and southern China; these advect intense cold air masses from Siberia to southern China.On the other hand, the weak surge is preceded by a negative SCAND pattern and a positive EU pattern.The corresponding wave train does not propagate from East Asia to the North Pacific.This wave train has a weak impact on the East Asian winter monsoon circulation and corresponds to weak cold air advections towards southern China.
Overall, the intra-seasonal variation of the Eurasian teleconnection patterns is crucial for a comprehensive understanding of the cold surge in southern China.