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Dynamics-Guided Analysis of Tropical Waves

Tropical waves are important tropical and global weather/climate systems as well as carriers for redistributing global energy. For
decades, a multitude of tropical wave theories that attempt to explain the origins and maintenance mechanisms of tropical waves and the
interactions between them and other tropical systems have been put forth by scientists. Partly due to the lack of effective analysis tools,
observational studies of tropical waves have not been comprehensive enough, leaving many of the proposed theories unverified. For example,
Fourier spectrum analysis based methods can hardly be used to obtain the accurate climatology of tropical waves because of the impacts of
locality. This study serves two purposes: (1) To introduce and develop novel dynamics-based effective methods and to tailor them for
isolating spatiotemporally local tropical waves of different spatiotemporal scales; and (2) To shed new insights into the climatological
features of tropical waves, such as life cycles, their interactions with other tropical phenomena, and their dynamical implications. To
accomplish the first goal, we introduce the multi-dimensional ensemble mode decomposition (MEEMD) method to decompose different
meteorological variables. This method is combined with our newly developed optimization methods based on tropical wave theory in this study
to form a dynamics based tropical wave diagnosis package. The capability of the new package is validated using both synthetic data and
observational data. It is demonstrated that our package has high capability of separating tropical waves of different spatiotemporal scales
as well as of different types. With the readiness of the above package, we systematically analyzed characteristic of tropical waves of
different types, with emphases being placed on the spatiotemporal structures and their life cycle. It is revealed that all types of tropical
waves have significantly different climatological characteristics, from wavenumbers and wave frequencies to their propagating properties. It
is revealed that that upper and lower tropospheric tropical waves have distinguishable dynamic characteristics, too different for researchers
to adopt a first baroclinic mode structure in the vertical to understand the origin and destiny of various tropical waves. We also quantify
the modulation characteristics of high frequency tropical waves by intraseasonal oscillations. / 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. / Fall Semester 2017. / October 31, 2017. / convectively coupled, locality, tropical waves / Includes bibliographical references. / Zhaohua Wu, Professor Directing Dissertation; Yiyuan She, University Representative; Mark A. Bourassa,
Committee Member; Ming Cai, Committee Member; Vasu Misra, Committee Member.

Identiferoai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_605019
ContributorsSun, Jie (author), Wu, Zhaohua (professor directing dissertation), She, Yiyuan (university representative), Bourassa, Mark Allan (committee member), Cai, Ming, 1957- (committee member), Misra, Vasubandhu, 1970- (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 (163 pages), computer, application/pdf

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