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The Impact of Tropical Cyclones on Upper Atmospheric Chemistry Using a High-Resolution Chemical Transport Model and Aircraft Observations

This research focuses on the transport of chemical species to the upper troposphere/lower stratosphere (UTLS) by tropical cyclones
(TCs). Species such as carbon monoxide, nitrogen oxides, and ozone have been found to exert a greater influence on climate change at these
high altitudes than if remaining near the surface. Typhoon Mireille (1991) is examined in the western North Pacific (WNP) Ocean basin using
in situ aircraft-derived chemical data from NASA's Pacific Exploratory Mission-West A field project. The Weather Research and Forecasting
(WRF) model was used with chemistry (WRF-Chem) at an innermost grid spacing of 3 km to explicitly resolve the convection being studied.
Results show that pollution from distant sources is ingested by Mireille and subsequently lofted by eyewall convection to the UTLS, enhancing
concentrations in this region. Flux calculations suggest that a strong TC, such as Mireille, can impact UTLS chemistry as much as a
continental middle latitude cyclone. Furthermore, overshooting cells in Mireille produced chemical flux density values at the tropopause
level as much as 10-20 times greater than that of the TC as a whole. Thus, although the overshooting tops comprise only a small area of the
total TC, they transport large quantities of gaseous species to the UTLS because of their very strong updrafts. Results also suggest that
millions of cars and/or several power plants would need to be hypothetically placed in the upper troposphere to have the same impact on
chemical concentrations as Mireille. This demonstrates the transport strength of the TC as a whole. Improved understanding of atmospheric
chemistry in the WNP basin is important, especially in the context of increasing Asian emissions and a changing climate. Furthermore, since
it has been hypothesized that global warming will lead to more intense storms, it is important to understand TCs’ role in chemical
transport. / A Dissertation submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment
of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2017. / August 3, 2017. / Atmospheric Chemistry, Climate, Deep Convection, Mesoscale Modeling, Tropical Cyclones / Includes bibliographical references. / Henry E. Fuelberg, Professor Directing Dissertation; David Van Winkle, University Representative; Mary
Barth, Committee Member; Robert E. Hart, Committee Member; Philip Sura, Committee Member; Guosheng Liu, Committee Member.

Identiferoai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_605006
ContributorsPreston, Aaron David (author), Fuelberg, Henry E. (professor directing dissertation), Van Winkle, David H. (university representative), Barth, Mary (committee member), Hart, Robert E. (Robert Edward), 1972- (committee member), Sura, Philip (committee member), Liu, Guosheng (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting departmentdgg)
PublisherFlorida State University
Source SetsFlorida State University
LanguageEnglish, English
Detected LanguageEnglish
TypeText, text, doctoral thesis
Format1 online resource (154 pages), computer, application/pdf

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