Physical Sciences and Mathematics Commons^™

Coastal Hurricane Damage Assessment Via Wavelet Transform Of Remotely Sensed Imagery, Ricky Carl Crowsey

Dissertations

This dissertation uses post storm imagery processed using wavelet transforms to investigate the capability of wavelet transform-based methods to classify post storm damage of residential areas. Five level Haar, Meyer, Symlets, and Coiflets wavelet transform decompositions of the post storm imagery are inputs to damage classification models of post hurricane and tornado damage. Hurricanes Ike, Rita, Katrina, and Ivan are examined as are the 2011 Joplin and Tuscaloosa tornadoes.

Wavelet transform-based classification methods yielded varying classification accuracies for the four hurricanes examined, ranging from 67 percent to 89 percent classification accuracy for classification models informed by samples from the storms …

A Study On The Turbulent Characteristics Within The Hurricane Boundary Layer, Sunwei Li

Electronic Thesis and Dissertation Repository

As the medium between the sea surface and the upper atmosphere in a hurricane, the Hurricane Boundary Layer (HBL) plays a key role in the overall dynamics of a tropical cyclone, and therefore turbulence exchanges within the HBL deserve a thorough investi- gation. However, since it is dangerous and difficult to take direct measurements within the HBL, studies of the HBL turbulence processes based on direct observations are rare. Thanks to the newly developed dropwindsonde equipped with a Global Position System (GPS) receiver, it is now possible to measure wind velocities and other meteorological variables with an unprecedented accuracy and …

Turbulence Measurement In The Atmospheric Boundary Layer Using Cellular Telephone Signals, Lee R. Burchett

Theses and Dissertations

This thesis investigated a new method for measuring the intensity of turbulence in the planetary boundary layer that shows a high correlation with measurements from weather radar. The method takes measurements of cell phone signal strength and uses scintillation in the signal to estimate the strength of local turbulence. Using cell phone signals provides unique measurement advantages: it is a passive measurement method, it is not strongly affected by precipitation, and one device can potentially measure several paths at once. The measurements were taken using an Android® cell phone running a custom built application. The strength of turbulence was quantified …

Ozone Measurements And Transport, Mohammed Kedir Osman

Electronic Thesis and Dissertation Repository

Ozone intrusions from the stratosphere to the troposphere occur as part of the Brewer-Dobson circulation, but the details of the microphysics of the process are unresolved. This research mainly focuses on near-tropopause regions, and examines stratospheric ozone intrusions into the troposphere across this stable zone. My research objective is to identify the small-scale atmospheric dynamical features responsible for the intrusion of stratospheric ozone into the troposphere, and to determine their relative importance from case to case.

Windprofiler radars, together with frequent ozonesonde launches, have been used to detect stratospheric ozone intrusions. This work has been supplemented by numerical simulation via …

Developing An Unstructured Grid, Coupled Storm Surge, Wind Wave And Inundation Model For Super-Regional Applications, Yi-Cheng Teng

Dissertations, Theses, and Masters Projects

During extreme weather conditions such as hurricanes and nor'easters, both the currents and wind waves generated by the atmospheric forces are important. Although they may act and dominate on different temporal and spatial scales, their interactions and combined effects are without doubt significant. In this dissertation, a major effort has been made to couple an unstructured grid circulation model SELFE (semi-implicit, Eulerian-Lagrangian finite element model) and the WWM II (Wind Wave model II). Moreover, this new coupled model system can be executed in a parallel computational environment. After the coupled model was successfully built, the model was verified with ideal …

Analysis Of Intraseasonal Convective Variability Modes Over West Africa During The Monsoon Season, Jeffrey Ceratto

Legacy Theses & Dissertations (2009 - 2024)

Intraseasonal variability of rainfall within the West African Monsoon has been shown to be an important factor in the weather of this region. Multiple factors have been found to contribute to variability at this timescale. Mounier, et al (2008) use EOF analysis to uncover and describe a quasi-stationary dipole of precipitation between the West African Monsoon system and the West Atlantic/Caribbean Sea. This mode, termed the Quasi Biweekly Zonal Dipole mode, operates on timescales of roughly 13 days. The stationary nature of this dipole is focused upon in their work, while the role of Kelvin waves in the mode are …

An Analysis Of The Formation And Evolution Of The 1989 Western North Pacific Subtropical Gyre, Brian Andrew Crandall

Legacy Theses & Dissertations (2009 - 2024)

This thesis conducts an observational study of a large cyclonic gyre that developed in the Western North Pacific (WNP) in late July 1989. For a period of six days, azimuthally-averaged winds at 850 hPa remained cyclonic out from the center of circulation to the 2000 km radius, with azimuthally-averaged tangential wind speeds at or greater than 10 m s-1. The gyre exhibited an asymmetric convection pattern, with the center, north and west flanks devoid of large convective areas, but the southern and eastern flanks maintained large-scale convective regions, extending as much as 4000 km in longitude.

A Wrf Simulation Of The Asymmetric Rapid Intensification And Trough Interaction Of Tropical Storm Gabrielle (2001), Diana Elizabeth Thomas-Abernethy

Legacy Theses & Dissertations (2009 - 2024)

Despite 13 ms-1 ambient wind shear, Tropical Storm (TS) Gabrielle underwent 22 hPa pressure falls within 3 hours prior to 0900 UTC 14 September. The rapid intensification of Gabrielle was atypical due to an upper-level trough approaching from the northwest. Additionally, a convective cell developed in the downshear left quadrant of the center, moved cyclonically and inward to the 17 km radius. During this time, The Tropical Rainfall Measurement Mission (TRMM) had one of its most intense 85 GHz scattering measurements ever (Molinari and Vollaro, 2010).

Appalachian Lee Troughs And Their Association With Severe Convective Storms, Daniel Thompson

Legacy Theses & Dissertations (2009 - 2024)

Forecasting convective storms in the mid-Atlantic region of the U.S. (hereafter mid-Atlantic) is important because of the proximity of the convective initiation region to major East Coast cities. These forecasts can be challenging because of the weak synoptic-scale forcing for ascent and abundant convective instability typical of the mid-Atlantic warm season (May-September). As a result, mesoscale boundaries such as the Appalachian lee trough (ALT) play an important role in initiating convective storms. This thesis examines the association between ALTs and warm-season severe convective storms in the mid-Atlantic in order to understand how ALTs modulate the frequency and distribution of severe …

Convectively-Coupled Kelvin Waves Over The Tropical Atlantic And African Regions And Their Influence On Atlantic Tropical Cyclogenesis, Michael John Ventrice

Legacy Theses & Dissertations (2009 - 2024)

High-amplitude convectively coupled atmospheric Kelvin waves (CCKWs) are explored over the tropical Atlantic during the boreal summer. Atlantic tropical cyclogenesis is found to be more frequent during the passage of the convectively active phase of the CCKW, and most frequent two days after its passage. CCKWs impact convection within the mean latitude of the inter-tropical convergence zone over the northern tropical Atlantic. In addition to convection, CCKWs also impact the large scale environment that favors Atlantic tropical cyclogenesis (i.e., deep vertical wind shear, moisture, and low-level relative vorticity).