Changes in occurrence of cold surges over east Asia in association with Arctic Oscillation

It has been newly found that the occurrence of cold surges in east Asia is significantly influenced by the Arctic Oscillation (AO). In the present study, the events of cold surge are objectively determined based on several synoptic criteria and the phase-dependency of its occurrences in association with the AO has been revealed. During the negative AO phase, the frequency of cold surge occurrence is relatively increased than that of neutral and positive AO phases. The variation of upper level trough and jet stream over east Asia and the Siberian High in association of AO are suggested to explain the change of cold surge occurrences.