Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean
2012 Fall. Includes bibliographical references. The quasi-geostrophic omega equation has been used extensively to examine the large-scale vertical velocity patterns of atmospheric systems. It is derived from the quasi-geostrophic equations, a balanced set of equations based on the partitioning of th...
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ftcolostateunidc:oai:mountainscholar.org:10217/71556 2023-06-11T04:14:59+02:00 Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean Dostalek, John F. Schubert, Wayne DeMaria, Mark Estep, Don Johnson, Richard Vonder Haar, Tom 2007-01-03T08:26:20Z born digital doctoral dissertations application/pdf http://hdl.handle.net/10217/71556 English eng eng Colorado State University. Libraries 2000-2019 - CSU Theses and Dissertations Dostalek_colostate_0053A_11376.pdf ETDF2012500297ATMS http://hdl.handle.net/10217/71556 Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright. Text 2007 ftcolostateunidc 2023-05-04T17:36:33Z 2012 Fall. Includes bibliographical references. The quasi-geostrophic omega equation has been used extensively to examine the large-scale vertical velocity patterns of atmospheric systems. It is derived from the quasi-geostrophic equations, a balanced set of equations based on the partitioning of the horizontal wind into a geostrophic and an ageostrophic component. Its use is limited to higher latitudes, however, as the geostrophic balance is undefined at the equator. In order to derive an omega equation which can be used at low latitudes, a new balanced set of equations is developed. Three key steps are used in the formulation. First, the horizontal wind is decomposed into a nondivergent and an irrotational component. Second, the Coriolis parameter is assumed to be slowly varying, such that it may be moved in and out of horizontal derivative operators as necessary to simplify the derivation. Finally, the mass field is formulated from the nondivergent wind field. The resulting balanced set of equations and the omega equation derived from them are valid over the whole sphere. In addition, they take a similar form to the quasi-geostrophic equations. The global omega equation is applied to the problem of tropical cyclogenesis in the Atlantic Ocean. The omega fields are used to compare those disturbances that eventually undergo cyclogenesis with those that dissipate. Composite analysis is employed and, in order to account for the different regional behavior of tropical cyclogenesis, the Atlantic is divided into three subbasins: the Tropics, the Subtropics, and the Gulf of Mexico. It is found that the large-scale omega is not strong enough to account for the magnitude of vertical velocities found in tropical cyclones, but acts to provide a favorable environment for convection to develop. The greatest difference between the developing composite and dissipating composite is seen in the Tropics, where the large-scale ascent at low levels on the leading edge of the disturbance due to frictional forcing in the ... Text North Atlantic Digital Collections of Colorado (Colorado State University) |
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Digital Collections of Colorado (Colorado State University) |
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language |
English |
description |
2012 Fall. Includes bibliographical references. The quasi-geostrophic omega equation has been used extensively to examine the large-scale vertical velocity patterns of atmospheric systems. It is derived from the quasi-geostrophic equations, a balanced set of equations based on the partitioning of the horizontal wind into a geostrophic and an ageostrophic component. Its use is limited to higher latitudes, however, as the geostrophic balance is undefined at the equator. In order to derive an omega equation which can be used at low latitudes, a new balanced set of equations is developed. Three key steps are used in the formulation. First, the horizontal wind is decomposed into a nondivergent and an irrotational component. Second, the Coriolis parameter is assumed to be slowly varying, such that it may be moved in and out of horizontal derivative operators as necessary to simplify the derivation. Finally, the mass field is formulated from the nondivergent wind field. The resulting balanced set of equations and the omega equation derived from them are valid over the whole sphere. In addition, they take a similar form to the quasi-geostrophic equations. The global omega equation is applied to the problem of tropical cyclogenesis in the Atlantic Ocean. The omega fields are used to compare those disturbances that eventually undergo cyclogenesis with those that dissipate. Composite analysis is employed and, in order to account for the different regional behavior of tropical cyclogenesis, the Atlantic is divided into three subbasins: the Tropics, the Subtropics, and the Gulf of Mexico. It is found that the large-scale omega is not strong enough to account for the magnitude of vertical velocities found in tropical cyclones, but acts to provide a favorable environment for convection to develop. The greatest difference between the developing composite and dissipating composite is seen in the Tropics, where the large-scale ascent at low levels on the leading edge of the disturbance due to frictional forcing in the ... |
author2 |
Schubert, Wayne DeMaria, Mark Estep, Don Johnson, Richard Vonder Haar, Tom |
format |
Text |
author |
Dostalek, John F. |
spellingShingle |
Dostalek, John F. Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
author_facet |
Dostalek, John F. |
author_sort |
Dostalek, John F. |
title |
Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
title_short |
Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
title_full |
Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
title_fullStr |
Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
title_full_unstemmed |
Global omega equation: derivation and application to tropical cyclogenesis in the north Atlantic Ocean |
title_sort |
global omega equation: derivation and application to tropical cyclogenesis in the north atlantic ocean |
publisher |
Colorado State University. Libraries |
publishDate |
2007 |
url |
http://hdl.handle.net/10217/71556 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
2000-2019 - CSU Theses and Dissertations Dostalek_colostate_0053A_11376.pdf ETDF2012500297ATMS http://hdl.handle.net/10217/71556 |
op_rights |
Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright. |
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