Browsing by Subject "Hurricanes"
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Item Assessing The Vulnerability Of Coastal Aquatic Ecosystem Stability And Structure After Hurricane Passage(2015) Davenport, Erik DePaul; Fan, Chunlei; Clark, Kelton; Biology; Doctor of PhilosophyThe primary objective of this research was to develop a framework of metrics for quantification and comparison of the ecological effects from hurricanes in coastal ecosystems. Many commercially important fishery species inhabit marine ecosystems that are exposed to risk from hurricane events. Understanding how the effects of hurricanes on biological production in coastal ecosystems are important for forecasting potential impacts to fishery resources. It is hypothesized that ecosystem stability and structure will display different levels of vulnerability to the passage of hurricanes with similar wind and precipitation. Through the use of numerical simulations, changes to biological production are examined relative to presumed changes in environmental factors caused by hurricane winds and precipitation. The results of these simulations are compared to observations in the literature. Vulnerability of ecosystems to hurricanes and the utility of numerical simulations as a resource management strategy are discussed.Item Coherent Turbulence in the Boundary Layer of Hurricane Rita (2005) during an Eyewall Replacement Cycle(American Meteorological Society (AMS), 2018-08-17) Guimond, Stephen; Zhang, Jun A.; Sapp, Joseph W.; Frasier, Stephen J.The structure of coherent turbulence in an eyewall replacement cycle in Hurricane Rita (2005) is presented from novel airborne Doppler radar observations using the Imaging Wind and Rain Airborne Profiler (IWRAP). The IWRAP measurements and three-dimensional (3D) wind vector calculations at a grid spacing of 250 m in the horizontal and 30 m in the vertical reveal the ubiquitous presence of organized turbulent eddies in the lower levels of the storm. The data presented here, and the larger collection of IWRAP measurements, currently are the highest-resolution Doppler radar 3D wind vectors ever obtained in a hurricane over the open ocean. Coincident data from NOAA airborne radars, the Stepped Frequency Microwave Radiometer, and flight-level data help to place the IWRAP observations into context and provide independent validation. The typical characteristics of the turbulent eddies are the following: radial wavelengths of ~1–3 km (mean value is ~2 km), depths from the ocean surface up to flight level (~1.5 km), aspect ratio of ~1.3, and horizontal wind speed perturbations of 10–20 m s−1. The most intense eddy activity is located on the inner edge of the outer eyewall during the concentric eyewall stage with a shift to the inner eyewall during the merging stage. The evolving structure of the vertical wind shear is connected to this shift and together these characteristics have several similarities to boundary layer roll vortices. However, eddy momentum flux analysis reveals that high-momentum air is being transported upward, in contrast with roll vortices, with large positive values (~150 m2 s−2) found in the turbulent filaments. In the decaying inner eyewall, elevated tangential momentum is also being transported radially outward to the intensifying outer eyewall. These results indicate that the eddies may have connections to potential vorticity waves with possible modifications due to boundary layer shear instabilities.Item Impacts of hurricane experience on risk perception and evacuation(2019-12) Laurence, Akeem Daniel Keven; Kedzior, Sya B.; Towson SeminarHurricanes are capable of catastrophic widespread destruction, posing a serious risk to human life that is best mitigated by early and complete evacuation of the storm’s path. This study seeks to understand the impact of hurricane experience on individuals risk perception and evacuation planning so future evacuation orders can be better tailored to increase evacuation rates and prevent loss of life during devastating hurricanes like Dorian (see Fig. 1). I conducted an online survey through Google Forms questioning 20 family members living in the Caribbean about their hurricane experience, forecast trust, and evacuation plans. Respondents volume of experience was compared to their responses on key questions in the survey, finding that greater experience correlated with lower forecast trust, risk perception, and evacuation likelihood. The conclusion can be drawn from my research that populations experienced with hurricanes will require targeted evacuation orders to bypass their lowered risk perception.