A Comparison of Kinetic Energy Budget Analyses Derived from the NCAR GCM and Observed Data

Abstract

A diagnostic energetics analysis of short-range, real-data forecasts produced by the NCAR General Circulation Model is performed by computing the forecast kinetic energy budget for a single case study and comparing it with budget statistics derived from observational data. Comparisons are made for the Northern Hemisphere as well as for a limited region encompassing most of North America. The hemispheric analysis reveals that significant losses of kinetic energy occur in the first 48 h of the forecast period. Also, computations of the kinetic energy generation and dissipation reveal that the model may be underestimating the intensity of the atmospheric energy cycle. Within the limited region the model captures the essential features of the large-scale flow, but fails to reproduce adequately the energy sources and sinks necessary for the development and subsequent propagation of a short synoptic-scale wave system.