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An observational study of the energy balance of the stationary disturbances in the atmosphere
Author(s) -
Holopainen E. O.
Publication year - 1970
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49709641006
Subject(s) - energy balance , baroclinity , diabatic , mechanics , kinetic energy , energy flow , energy transformation , standing wave , atmosphere (unit) , thermal energy , environmental science , potential energy , perturbation (astronomy) , mean flow , turbulence , mechanical energy , meteorology , atmospheric sciences , physics , energy (signal processing) , classical mechanics , thermodynamics , adiabatic process , power (physics) , optics , quantum mechanics
Different terms in the equations describing the balance of kinetic energy and available potential energy in the so‐called stationary disturbances or standing waves (deviation of the atmosphere's time‐mean flow from axial symmetry) are evaluated approximately by using the observational statistics of the atmospheric flow. Because many simplifications and assumptions have been necessary in order to get estimates of certain terms, the results only give a rough first‐estimate picture about the maintenance of the stationary disturbances. The results indicate that in winter the stationary disturbances are typically baroclinic waves, which get available potential energy from the temperature distribution of the zonally‐averaged mean flow and partly convert it into kinetic energy to offset the destructive effect on the latter by small‐scale turbulent friction, large‐scale transient motions and conversion into zonally‐averaged mean motion. The most important ‘ external ’ forcing seems, from the energy point of view, to be the stationary heat sources and sinks, which in winter destroy the available potential energy of the stationary disturbances; the effect of mountains in the energy balance of the standing waves seems to be relatively minute and actually smaller than the kinematic and thermal effects of large‐scale transient flow systems. In summer the stationary disturbances appear to form a thermally‐driven system, where the frictional loss of kinetic energy is compensated for by a conversion from the available potential energy, which in turn is maintained by generation due to diabatic heating.