Energy Sources in Middle–Latitude Synoptic–Scale Disturbances

Abstract

Energy source terms in various types of mid–latitude synoptic–scale disturbances are examined with wore than 3400 computed synoptic cases during a 5–year period over North America. It is shown that cyclones and cyclone vicinities serve as the baroclinic energy source regions, although the released energy through the eddy conversion process may be transported to other regions for generation of the kinetic energy. In the development and mature stages of cyclonic disturbances the eddy energy conversion is very active both within the cyclones and their vicinities. When cyclones are occluded the cyclone vicinities lose their importance as the baroclinic source region. In contrast to cyclonic disturbances, anticyclonic disturbances destroy kinetic energy. In intermediate type disturbances there is a significant generation of kinetic energy. However, there is no internal energy source through the eddy conversion in these disturbances, and they depend on imported potential energy for their kinetic energy generation.