Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Tornadic"”.
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Multiscale environmental flow dynamics: particle settling, turbulence modulation, and tornadic vortices
Environmental flows form the basis of processes that span sediment transport in rivers, drag reduction in pipelines, and the evolution of severe atmospheric vortices. Despite significant efforts to address related phenomena, a predictive, mechanistic description of how particles, non‑Newtonian …
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The Role of Topography on the 7 June 2012 Tornadic Supercell near Wheatland, WY
… storm near Laramie, WY and made it become tornadic. This study intended to find out whether these two tornadoes occurred under similar conditions. Stability, shear, low-level and upper-level environmental conditions, and radar and satellite imagery were used to asses this storm’s formation …
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Mesoscale and stormscale ingredients of tornadic supercells producing long-track tornadoes in the 2011 Alabama super outbreak
… such as instability and shear, to long-track tornadic storm structure. Properties of simulated soundings, for instance hodograph length and curvature, 0-1km storm relative helicity [SRH], 0-3km SRH and convective available potential energy [CAPE] properties are compared to idealized soundings …
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The observed relationship between tornado intensity and pretornadic mesocyclone characteristics and environments
… was assembled that focuses explicitly on the pre-tornadic characteristics of the mesocyclone, such as width and differential velocity: the pre-tornadic focus allows us to eliminate the effects of the tornado itself on the mesocyclone characteristics. GR2Analyst was used to manually analyze 80 …
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Understanding tornado intensity in supercells and quasi-linear convective systems
… the first part, a theoretical framework linking tornadic storm updraft characteristics to tornado intensity is further explored. An application of Kelvin’s circulation theorem to pre-tornadic and tornadic circulations shows that initial tornadic circulations are necessarily constrained by the …
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Characterizing and Forecasting Severe Convective Storms using Deep Learning
… investigates the dynamics and predictability of tornadic supercell environments, leveraging advanced data analysis and machine learning techniques. Initial research established a foundation by examining the spatial and temporal variability of tornado-favorable parameters using reanalysis data. …
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Tornadogenesis And Tornadogenesis Failure In Numerically Simulated Supercells
… longest-lived supercells.</p> <p> Twenty-one tornadic simulations were examined. It was found that 0-3 km storm relative environmental helicity was the best predictor of the intensity (i.e. maximum pressure drop) and duration of the simulated tornadoes. A trajectory analysis found that …
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The Association of Strong Near-Surface Wind Shear Profiles with Enhanced Probabilities of Significant Severe Weather and Tornado Events.
… and directional shear has been noted in pre-tornadic vertical wind profiles. This combination consists of intense speed shear followed by intense directional shear between the surface and 1 km AGL, which appears as a sickle-shape on a hodograph. A composite sickle-shaped hodograph was …
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Impacts of cold pool strength on tornado production in quasi-linear convective systems
… pre-convective line vertical wind shear for 94 tornadic and nontornadic QLCSs in the central and eastern United States from 2017–2022. Cold pool strength was quantified by the virtual potential temperature perturbation from the base state using 1-minute observations from Automated Surface …
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Thermodynamic, kinematic, and radar parameters of isolated tornadoes with and without NWS warning
… cells using a dBZ threshold of 35. The tornadic cell was analyzed among multiple radar parameters using paired Student t-tests to find any significant difference between WARN and NOWARN at time of tornado formation and 30 minutes before formation, as well as between nearby nontornadic …
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Computer Modeling of the Influence of Structure Plan Areas on Tornado Forces
… buildings and attempted to distinguish between tornadic wind loads and SL flow loads. Using a computer simulation, this research addresses and distinguishes between the tornadic forces and SL forces on structures. In the numerical simulation, tornado forces and SL forces will be compared on …
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A Case Study of a High-Precipitation Supercell-Bow Echo Transition on 4-5 June 2008
… and is compared to previous observations of tornadic and non-tornadic low-level mesocyclones. It is hypothesized that the merger of the nascent supercell with a HP supercell initiated its SBE transition. This merger resulted in the development of an updraft bridge which led to an increase in …
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Large -eddy simulation of a three-dimensional compressible tornado vortex
… LES model, three different patterns of tornadic corner flows cataloged by local swirl ratio are simulated under quasisteady conditions for different Mach numbers. Simulation comparisons have demonstrated that the compressibility effects are different for different corner flow structures. …
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Improving Storm-Scale Analyses of Convection via Assimilation of Polarimetric Radar Observations
… field evolution associated with a significantly tornadic supercell thunderstorm. This included the identification of a specific differential phase foot and differential reflectivity shield as well as the first documentation focused on the relationship between polarimetric field evolution relative …
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Assessing the impacts of microphysical and environmental controls on simulated supercell storms
… to better detect environments that can produce tornadic supercells in advance. Therefore, the goals of the research presented in Chapter 3 are to (1): understand the storm processes that change as environmental conditions of supercells are perturbed and (2): determine how sensitive platforms, …
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Storm mergers and their role in tornado genesis during the 2011 Joplin storm
… of the parent rotating updraft (mesocyclone) and tornadic vortex in the 22 May 2011 Joplin, MO case. This case was noted for the rapid evolution of the storm from tornado formation (tornadogenesis) to peak intensity in relation to the merging of cells in the rear-flank region of the parent storm. …
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High resolution numerical simulation of a nocturnal mesoscale convective system: Comparison with pecan observations
… wind and hail reports, as well as at least one tornadic supercell. In order to expand upon the impact of microphysical processes on the kinematic evolution of the storm sampled by the P3, the WRF-ARW model was used to run high-resolution numerical simulations which would help highlight in detail …
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Insights into tornadogenesis and tornado dynamics from idealized simulations
… parameters can cause a bifurcation between the tornadic and nontornadic cases, demonstrating the nonlinearity of tornadogenesis. The relative importance of the updraft and cold pool intensities depends on the position within the 2D spectrum spanned by the two parameters, with e.g., …
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Dynamic impact induced by tornadoes through simulations based on two-way wind-structure interactions
… on civil structures, based on which design tornadic wind loading can be properly determined. To achieve this, in this study, Computational Fluid Dynamics (CFD) simulations and Computational Structural Dynamics (CSD) simulations are combined for the first time to systematically investigate …
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Behavior of Wind Turbine Towers and Blades Under Tornado Wind Fields
… several tornado wind fields with different tornadic structures. It also accounted for the configuration of the blades (pitch angle changes), various airfoil sections, the rotor configuration (yaw angle changes), the supporting tower’s height (hub height), and the base diameter of the …
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