Energy transformations in middle‐latitude disturbances

In an attempt to study the ensemble energetics properties of various types of the middle‐latitude synoptic‐scale disturbances, the kinetic energy balance is computed over a defined large area twice daily during a five‐year period. Prevailing flow patterns are examined with daily synoptic charts to group individual synoptic cases and evaluate the mean energy budgets according to the different types of disturbances. Eleven categories of transient disturbances, including various cyclonic, anticyclonic, and intermediate flow types, are considered. The balance of source and sink terms in the cyclonic and intermediate types of disturbances is basically similar with maximum generation and dissipation in the lower troposphere and at the jet stream level. However, in the anticyclonic disturbances there is adiabatic destruction of kinetic energy in the upper troposphere through cross‐isobaric flow with a negative dissipation which may indicate a required supply of kinetic energy from other scales of motion in the maintenance of the anticyclonic flow. Different degrees of cyclonic and anticyclonic developments are also reflected in the intensity of the energy transformation rate and the manifestation of the transport terms. A number of individual synoptic cases are also examined.