Year: 1990
Type: dissertation
Abstract: This thesis is devoted to the study of exergy and its application to the atmosphere.A method is developed to calculate the local column balances of the global closed-system exergy in connection to an extended general circulation model system, the weather forecast model at the European Centre for Medium Range Weather Forecasts (ECMWF), Reading, England.The exergy calculations take full advantage of the model formulation, e.g., the method correctly includes topography and moisture.For this work it has also been necessary to develop the field of exergetics itself.A relation between the closed-system exergy and the corresponding open-system exergy is demonstrated.The local exergy balance for a hydrodynamic fluid mixture with chemical reactions in an external body force field is derived, as well as a set of useful relations for the open-and closed-system exergy for the case of a time-dependent reference state.The improved atmospheric exergetics has also led to a contribution to atmospheric physics.The relations between exergy and some other energetic concepts used in atmospheric studies are analysed: various forms of available potential energy, entropic energy, entropic potential energy, gross static stability and available enthalpy.Some diagnostics on the exergy balance in the atmosphere is presented and a thermodynamically relevant efficiency factor for the atmospheric energy cycle is calculated.The methodological developments and the results may contribute to a better understanding of various features of physical resources in natural systems: The balance of the exergy, a valuable physical resource concept, is applied to an important natural system, the atmosphere, which is treated as a dissipative structure, a system converting and destroying exergy and exchanging exergy with external sources and sinks.Thereby estimates of the limits to, and possibilities for extraction of, exergy resources, already in use in society or of potential future interest, may be facilitated.
Author: Sten Karlsson
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W275316402