The structure and energetics of midlatitude disturbances accompanying cold-air out-breaks over East Asia.

It is seen that high-frequency disturbances accompanying cold surges experience systematic structural changes as they migrate along a well-defined storm track from East Asia to the Gulf of Alaska. The typical life cycle of such extratropical storms is characterized by a baroclinic growth phase coinciding with the polar outbreaks, and a decay phase in which barotropic processes play an active role. The findings of this composite study are seen to be consistent with circulation statistics derived from continuous climatological records. The behavior of the fluctuations with short and long time scales is also reminiscent of the characteristics of baroclinically unstable waves and Rossby-wave trains, respectively, appearing in model experiments. -from Authors