Persistent Link:
http://hdl.handle.net/10150/187480
Title:
An analysis of the genesis of Hurricane Guillermo (1991).
Author:
Farfan Molina, Luis Manuel.
Issue Date:
1996
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A case study of tropical cyclogenesis in the eastern Pacific Ocean is investigated. The tropical cyclone developed in 1991 during the Tropical Experiment in Mexico (TEXMEX) project. In this case study, the initial circulation originated west of Central America and after a period of intensification this circulation became Hurricane Guillermo. The purpose of this research is to identify the physical mechanisms that are active in the formation of the initial circulation and the role that the topography plays in this formation. A documentation of the characteristics of the large scale-flow present prior to the detection of the initial circulation is performed. The observations used include data derived from upper-air soundings and satellite imagery. These observations show that a synoptic-scale easterly wave moved over the Caribbean Sea and while the wave approached the topography of Central America, a low-level, mesoscale circulation developed over the eastern Pacific. It is observed that the modification of the easterly flow by the mountains is an important element in organizing the initial circulation. In order to investigate the dynamics involved in the formation of the circulation model simulations are performed. The objective of these simulations is to reproduce the formation of the circulation and analyze the contribution from the topographic modification of the flow in the formation of the vortex. This objective is accomplished by performing numerical simulations with a mesoscale model. The model fields indicate that the initiation of the circulation occurred while the easterly wave axis moved close to the mountains of Central America. The changes in the direction of the upstream easterly flow, induced by the wave, and the deflection of the winds by the mountains generated a pair of easterly jets in the eastern Pacific. These two elements, along with the Intertropical Convergence Zone (ITCZ), provided a mesoscale area of enhanced vorticity that defined the formation of a closed circulation. A further intensification of the circulation occurred and the storm evolved into a stronger system.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Atmospheric Sciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Zehnder, Joseph A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleAn analysis of the genesis of Hurricane Guillermo (1991).en_US
dc.creatorFarfan Molina, Luis Manuel.en_US
dc.contributor.authorFarfan Molina, Luis Manuel.en_US
dc.date.issued1996en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA case study of tropical cyclogenesis in the eastern Pacific Ocean is investigated. The tropical cyclone developed in 1991 during the Tropical Experiment in Mexico (TEXMEX) project. In this case study, the initial circulation originated west of Central America and after a period of intensification this circulation became Hurricane Guillermo. The purpose of this research is to identify the physical mechanisms that are active in the formation of the initial circulation and the role that the topography plays in this formation. A documentation of the characteristics of the large scale-flow present prior to the detection of the initial circulation is performed. The observations used include data derived from upper-air soundings and satellite imagery. These observations show that a synoptic-scale easterly wave moved over the Caribbean Sea and while the wave approached the topography of Central America, a low-level, mesoscale circulation developed over the eastern Pacific. It is observed that the modification of the easterly flow by the mountains is an important element in organizing the initial circulation. In order to investigate the dynamics involved in the formation of the circulation model simulations are performed. The objective of these simulations is to reproduce the formation of the circulation and analyze the contribution from the topographic modification of the flow in the formation of the vortex. This objective is accomplished by performing numerical simulations with a mesoscale model. The model fields indicate that the initiation of the circulation occurred while the easterly wave axis moved close to the mountains of Central America. The changes in the direction of the upstream easterly flow, induced by the wave, and the deflection of the winds by the mountains generated a pair of easterly jets in the eastern Pacific. These two elements, along with the Intertropical Convergence Zone (ITCZ), provided a mesoscale area of enhanced vorticity that defined the formation of a closed circulation. A further intensification of the circulation occurred and the storm evolved into a stronger system.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAtmospheric Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairZehnder, Joseph A.en_US
dc.contributor.committeememberKrider, E. Philipen_US
dc.contributor.committeememberMullen, Steven L.en_US
dc.contributor.committeememberSchowengerdt, Roberten_US
dc.identifier.proquest9626513en_US
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