Evaluating the Impacts of Eastern North Pacific Tropical Cyclones on North America Utilizing Remotely Sensed and Reanalysis Data

Persistent Link:
http://hdl.handle.net/10150/238676
Title:
Evaluating the Impacts of Eastern North Pacific Tropical Cyclones on North America Utilizing Remotely Sensed and Reanalysis Data
Author:
Wood, Kimberly
Issue Date:
2012
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.
Embargo:
Release after 20-Jan-2013
Abstract:
The eastern North Pacific Ocean has the highest density of tropical cyclone genesis events of any tropical basin in the world, and many of these systems form near land before moving westward. However, despite the level of tropical cyclone activity in this basin, and the proximity of the main genesis region to land, tropical cyclone behavior in the eastern North Pacific has been relatively unexplored. When synoptic conditions are favorable, moisture from northward-moving tropical cyclones can be advected into northern Mexico and the southwestern United States, often leading to the development of summertime thunderstorms during the North American monsoon season. An interaction with a mid-latitude trough produces the most rainfall, and the spatial variability of precipitation is greatly affected by the complex topography of the region. Moisture can be advected from a tropical cyclone around the subtropical ridge in place for much of the eastern North Pacific hurricane season and contribute to precipitation. This ridge, when it extends westward over the Pacific Ocean, can also prevent tropical cyclone moisture from impacting the southwestern United States. Northward-moving tropical cyclones often enter an environment with decreasing sea surface temperatures, increasing vertical wind shear, and meridional air temperature and moisture gradients. These key ingredients for extratropical transition are generally present in the eastern North Pacific, but the subtropical ridge prevents many named systems from moving northward, and only 9% of eastern North Pacific tropical cyclones from 1970 to 2011 complete ET according to cyclone phase space. However, over half of the systems that do not complete ET dissipate as cold core cyclones, a structural change that has yet to be explored in other tropical basins. It is difficult to estimate tropical cyclone intensity in a vast ocean area with few direct measurements available. The deviation angle variance technique, an objective method independent of the current techniques widely used today, was successfully applied to seven years of eastern North Pacific tropical cyclones. The RMS error of 13.5 kt for all seven years is comparable to the RMS errors found for other basins.
Type:
text; Electronic Dissertation
Keywords:
monsoon; precipitation; tropical cyclones; Atmospheric Sciences; eastern North Pacific; extratropical transition
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Atmospheric Sciences
Degree Grantor:
University of Arizona
Advisor:
Ritchie, Elizabeth

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleEvaluating the Impacts of Eastern North Pacific Tropical Cyclones on North America Utilizing Remotely Sensed and Reanalysis Dataen_US
dc.creatorWood, Kimberlyen_US
dc.contributor.authorWood, Kimberlyen_US
dc.date.issued2012-
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.releaseRelease after 20-Jan-2013en_US
dc.description.abstractThe eastern North Pacific Ocean has the highest density of tropical cyclone genesis events of any tropical basin in the world, and many of these systems form near land before moving westward. However, despite the level of tropical cyclone activity in this basin, and the proximity of the main genesis region to land, tropical cyclone behavior in the eastern North Pacific has been relatively unexplored. When synoptic conditions are favorable, moisture from northward-moving tropical cyclones can be advected into northern Mexico and the southwestern United States, often leading to the development of summertime thunderstorms during the North American monsoon season. An interaction with a mid-latitude trough produces the most rainfall, and the spatial variability of precipitation is greatly affected by the complex topography of the region. Moisture can be advected from a tropical cyclone around the subtropical ridge in place for much of the eastern North Pacific hurricane season and contribute to precipitation. This ridge, when it extends westward over the Pacific Ocean, can also prevent tropical cyclone moisture from impacting the southwestern United States. Northward-moving tropical cyclones often enter an environment with decreasing sea surface temperatures, increasing vertical wind shear, and meridional air temperature and moisture gradients. These key ingredients for extratropical transition are generally present in the eastern North Pacific, but the subtropical ridge prevents many named systems from moving northward, and only 9% of eastern North Pacific tropical cyclones from 1970 to 2011 complete ET according to cyclone phase space. However, over half of the systems that do not complete ET dissipate as cold core cyclones, a structural change that has yet to be explored in other tropical basins. It is difficult to estimate tropical cyclone intensity in a vast ocean area with few direct measurements available. The deviation angle variance technique, an objective method independent of the current techniques widely used today, was successfully applied to seven years of eastern North Pacific tropical cyclones. The RMS error of 13.5 kt for all seven years is comparable to the RMS errors found for other basins.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectmonsoonen_US
dc.subjectprecipitationen_US
dc.subjecttropical cyclonesen_US
dc.subjectAtmospheric Sciencesen_US
dc.subjecteastern North Pacificen_US
dc.subjectextratropical transitionen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineAtmospheric Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorRitchie, Elizabethen_US
dc.contributor.committeememberHirschboeck, Katherineen_US
dc.contributor.committeememberTyo, J. Scotten_US
dc.contributor.committeememberSerra, Yolandeen_US
dc.contributor.committeememberRitchie, Elizabethen_US
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