Stratospheric origin of cold surge occurrence in East Asia

In the present study, we have found a precursory signal in the stratospheric circulation prior to the cold surge occurrence in East Asia. Over northern Eurasia, about one week before the cold surge occurrence, strong stratospheric negative potential vorticity anomalies and rising of geopotential height are observed. The dynamic linkage between the stratospheric perturbations and the tropospheric adjustment, along with initial disturbances for a cold surge occurrence, are discussed.