Long-term change of synoptic wave patterns related to cold surge in the East Asia

Abstract

The cold surge is a distinct phenomenon of the East Asian winter monsoon. In recent 10 years, winter temperature of Korea has not shown any clear increasing trend despite steady increasing trend in annual mean temperature. One is a wave-train type related to the south-eastward expansion of the Siberian High The other is the blocking type. In our study, it is found that the occurrence frequency of the blocking type cold surge tends to increase in the last 30 years. This is largely attributed to the winter-mean circulation change over the Northern Siberia in the last 30 years. Although further research is needed to identify more concrete dynamic linkage, it is likely that more favorable background circulation pattern could favor occurrence of blocking induced cold surge over the northeast Asia.