Degree Type

Dissertation

Date of Award

1983

Degree Name

Doctor of Philosophy

Department

Geological and Atmospheric Sciences

Abstract

The energetics of standing and transient eddies simulated by the GLAS Climate Model (CM) and the NCAR Community Climate Model (CCM) in both winter and summer are compared in the physical and spectral domains to provide insight into their structure and maintenance and possible clues for the improvement of the models. Particular attention is focused on the 3-dimensional distributions of the energetics of standing eddies. Contributions from the long-wave regime to the standing eddies are also examined;In the winter Northern Hemisphere, it is found that the structure of standing eddies is closely associated with the distribution of continents and oceans, and that the maintenance of standing eddies is closely related to the jet streams. It is worth noting that over the eastern and western Pacific and Atlantic Oceans, where the standing eddy kinetic energy is most prominent, there are strong conversions from both the standing eddy available potential energy and the mean zonal flow kinetic energy to the standing eddy kinetic energy. The structure and maintenance of transient eddies correspond well with the features of the major storm tracks. The transient eddies tend to dissipate the standing eddies at locations where standing eddies are intense;Standing eddy energies and conversions are dominated by long waves in both models. In both models, standing long waves are generally not strong enough. It is noted that, in the NCAR CCM, both the available potential and kinetic energies of the total and standing wavenumber 2 are stronger than the GLAS CM;The topography and the land-sea contrast are similar between these two models. And it is noted that the geographical distributions of the thermal and dynamic fields of standing eddies and their related conversions are closely related to the strength and location of the jet streams which is essentially maintained by the diabatic heating fields. In addition, the more realistic simulation of jet streams by the NCAR CCM has been attributed to the more proper treatment in the radiative processes. Therefore, it is suggested that the differences in the behavior of standing eddies between these two models are primarily due to the differences in their heating fields.

DOI

https://doi.org/10.31274/rtd-180813-7998

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Yen-Huei Lee

Language

en

Proquest ID

AAI8323295

File Format

application/pdf

File Size

204 pages

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