자료유형  

 학위논문

Control Number  

0015492729

International Standard Book Number  

9781088324653

Dewey Decimal Classification Number  

551

Main Entry-Personal Name  

Smith, Warren Paul, II.

Publication, Distribution, etc. (Imprint  

[Sl] : University of Colorado at Boulder, 2019

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2019

Physical Description  

124 p

General Note  

Source: Dissertations Abstracts International, Volume: 81-05, Section: B.

General Note  

Advisor: Nicholls, Melville.

Dissertation Note  

Thesis (Ph.D.)--University of Colorado at Boulder, 2019.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약Before a hurricane forms, a process known as tropical cyclogenesis must occur during which a tropical disturbance transforms into a tropical depression. In order to further understand how and when hurricanes will form, we must start by examining the processes that lead to tropical cyclogenesis. This dissertation employs numerical modeling techniques to highlight the roles that both low-level vorticity and longwave and shortwave radiation play in this transformation.Recent numerical modeling and observational studies indicate the importance of vortical hot towers (VHTs) in tropical cyclogenesis. It has recently been recognized that convective-scale downdraft outflows that form within VHTs also preferentially develop positive vertical vorticity around their edges which is considerably larger in magnitude than ambient values. During a numerical simulation of tropical cyclogenesis it is found that particularly strong small-scale low-level convectively-induced positive vertical vorticity anomalies (herein termed ``LCVAs'') occasionally form as convection acts on the enhanced vorticity at the edges of cold pools. The LCVAs studied are considerably deeper than the vorticity produced at the edges of VHT cold pool outflows, and their evolution is associated with persistent convection and vortex merger events which act to sustain them. This dissertation highlights the formation and evolution of two representative LCVAs and discusses the environmental parameters which eventually become favorable for one LCVA to reach the center of a larger-scale circulation as tropical cyclogenesis occurs.Recent literature also indicates the importance of longwave and shortwave radiation in TCG. Herein we examine the sensitivity of TCG to radiation in both idealized simulations for different initial vortex strengths, and in a case study framework of Atlantic Hurricane Matthew (2016) to highlight when during tropical cyclogenesis radiation is most important. It is shown that all else equal, a stronger initial vortex reduces the impact that radiation has on accelerating tropical cyclogenesis. In both modeling frameworks we find that radiation's primary role is to moisten the core of a disturbance, and after sufficient moistening occurs over a deep layer and the winds are sufficiently strong at the surface, radiation no longer plays as significant a role in tropical cyclogenesis.

Subject Added Entry-Topical Term  

Atmospheric sciences

Subject Added Entry-Topical Term  

Meteorology

Subject Added Entry-Topical Term  

Vortices

Subject Added Entry-Topical Term  

Radiation

Subject Added Entry-Topical Term  

Cyclones

Added Entry-Corporate Name  

University of Colorado at Boulder Atmospheric and Oceanic Sciences

Host Item Entry  

Dissertations Abstracts International. 81-05B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:565008