Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 33-35). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 33-35). Also available on the Internet.

Thesis (M.S. in Meteorology)--Naval Postgraduate School, March 2005. / Thesis Advisor(s): Jeffrey B. Knorr, Carlyle H. Wash. Includes bibliographical references (p. 75-77). Also available online.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 104-115).

This thesis details the ACTIVE campaign in the tropics of northern Australia during 2005-2006 (based in Darwin). The focus of the campaign was to find the influence of tropical convection on the aerosol and chemical content of the Tropical Tropopause Layer [TTL] and the cirrus cloud cover in the area, which is important for the global energy budget. This study details the background climatology of the Darwin region with statistical categorisation of the trace gases and particles. The TTL had regions of extremely high aerosol number concentration, much higher than that of the PBL. The 10 to 1000 nm particle concentrations were as high as 25,000 cm-3 and 100 to 1000 nm were as high as 1000 cm-3. High aerosol concentrations were usually found in cloud-free conditions; cloudy regions were typically low in aerosol number. Wind data and trajectories (BADC) were used to find the origin of the high particle concentrations. Aerosols were found to be nucleating in outflow regions of convective anvils. SO2 oxidation to H2SO4 is a widely accepted mechanism for nucleation. A binary mechanism (H2O-H2SO4), with SO2 as the precursor, was found to be inadequate in explaining the nucleation and growth rates -- tested using an aerosol sectional model. However, it was found, via back trajectory analysis, that the climatology of Darwin was influenced by local and long-range sources, including advection from Indonesia and the Tropical Warm Pool. These distant sources could have introduced condensable matter, with aerosol precursor properties (certain organic compounds). The aerosol model found a condensable precursor concentration of at least 300 pptv was necessary to replicate the observations.

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abstract: Severe weather affects many regions of the United States, and has potential to greatly impact many facets of society. This study provides a climatological spatial analysis by county of severe weather warnings issued by the National Weather Service (NWS) between January 1st, 1986 to December 31st, 2017 for the contiguous United States. The severe weather warnings were issued for county-based flash flood, severe thunderstorm, and tornado phenomena issued through the study period and region. Post 2002 severe weather warnings issued by storm warning area were included in this study in the form of county-based warnings simultaneously issued for each affected county. Past studies have researched severe weather warnings issued by the NWS, however these studies are limited in geographic representation, study period, and focused on population bias. A spatial analysis of severe weather warning occurrences by county identify that (a) highest occurrences of flash flood warnings are located in the desert Southwest and Texas, (b) severe thunderstorm warning occurrence is more frequent in Arizona, portions of the Midwest, the South, and the Mid and South Atlantic states, (c) the tornado activity regions of Tornado Alley and Dixie Alley (i.e. Colorado, Kansas, Oklahoma, Arkansas, Texas, Louisiana, Mississippi, Alabama, Tennessee, and Illinois) contained the highest occurrences of tornado warnings, and (d) the highest instances of aggregate warning occurrences are found in the desert Southwest, the Midwest, and the Southern regions of the United States. Generally, severe weather warning “hot spots” tend to be located in those same regions, with greater coverage. This study concludes with a comparison of local maxima and general hot spot regions to expected regions for each phenomenon. Implications of this study are far reaching, including emergency management, and has potential to reduce risk of life. / Dissertation/Thesis / Masters Thesis Geography 2019

Project Completion Report, OWRT Project No. A-049-ARIZ / Agreement No. 14-31-0001-4003 / Project Dates: July 1, 1973 - June 30, 1974. / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964. / A non-linear reservoir model is used to represent the rainfall-runoff relationships for thunderstorms on the urban watersheds of Tucson, Arizona. Two types of computer programs are developed: a calibration program to obtain a best -fit calculated hydrograph; and a verification program to generate storm hydrographs given the watershed characteristics and a hyetograph. Calibration reveals the relationship of the model parameters, namely, (f) the inflow coefficient, (a) the constant coefficient, and (TL) the time lag, to the total rainfall, drainage area, channel length, and infiltration capacity of the watershed. The average discrepancy between the predicted hydrograph and the actual hydrograph for Tucson urban watersheds is 20 -25 percent.

Weather forecasting relies on the availability of observational data as input parameters. However,such data are not readily available, because of difficulties to collect weather data due toinaccessibility to many places in the world, such as oceans or mountain regions. For this reason,satellite surveillance is a suitable tool to observe the atmosphere in regions where it is notpossible by other means. This master thesis is a study of convective cloud cluster formation over Thailand, conductedthrough satellite image analysis. Characteristics of cloud cluster formations are investigatedthrough an implementation of the Maximum Spatial Correlation Technique (MASCOTTE),described by Carvalho and Jones (2001). This method allows tracking of convective cloud systemsthrough region based analysis of satellite images. The aim of this study is to investigate whether satellite image analysis, through the implementationof the MASCOTTE methodology, can provide characteristics of convective cloud systems,in order to discern convective systems by intensity, accurately enough to be able to discernsevere thunderstorms from ordinary thunderstorms. The annual distribution of the occurrenceof life cycles detected through the analysis is studied, as well as their monthly distribution ofmean and maximum life times. Moreover, the yearly distribution of life cycle mean and minimumbrightness temperatures are analysed, as well as the number of detected split and mergeevents. This is followed by a comparison of life cycle structural properties to investigate thepossibility to use individual parameters, alone or in combination with each other, as indicatorsof the degree of convective activity within life cycles. Yearly distributions were studied in order to verify if this method could reveal seasonal variations,such as the onset period of the wet season, in terms of the occurrence of life cycles andtheir life time. The findings of this study verified that the most convectively intense life cycles exist under theinfluence of the Inter Tropical Convergence Zone (ITCZ), during the onset and beginning ofthe monsoon season. Analysis of life cycle structural properties, showed that properties likemean and minimum brightness temperature as well as fractional convective area, could be usedas indicators to discern between life cycles with different level of convective activity. However,it is concluded that studies, including ground-based remote sensing technologies such asRADAR/LIDAR, as well as data from rawinsondes, needs to be conducted in order to clarifyif it is possible to use this methodology to successfully discern severe thunderstorms fromordinary thunderstorms. / Tillgängligheten av meteorologiska mätdata är väsentlig för att kunna prognostisera väder. Idag är tillgängligheten på dessa data relativt gles, bland annat på grund av svårigheter att mäta på många platser runt om i världen, t.ex över världshaven eller vid otillgängliga bergsområden. Därför är satellitövervakning ett bra alternativ till andra typer av väderobservationer, eftersom denna teknik kan tillhandahålla mätdata över stora områden som annars inte är möljiga att samla data från. Denna magisteruppsats är en studie om egenskaper hos konvektiv molnbildning över Thailand. Studien är genomförd med hjälp av satellitbildsanalys. Egenskaper hos olika konvektiva molnceller har studerats genom att använda en metod baserad på ”the Maximum Spatial Correlation Technique” (MASCOTTE), beskriven av Carvalho and Jones (2001). Tanken bakom denna metod är att hitta och följa utvecklingen av olika konvektiva molnceller baserat på deras storlek och temperatur. Målet med studien är att undersöka hurvida denna metoden kan ge kunskap som leder till att man kan skilja på konvektiva celler, genom intensitetsskillnader, med tillräcklig noggrannhet för att kunna urskilja vanliga konvektiva celler från intensiva celler. För att få en uppfattning om förekomsten av intensiva konvektiva system, har antalet detekterade livscykler per månad studerats. För sedan att få en bild av hurvida deras livscykler skiljer sig åt över året, har även egenskaper som medellivslängd och maximal livslängd studerats. Dessutom studerades den årliga fördelningen av livscyklernas medel och minimum temperaturer, samt förekomsten av delningar och sammanslagningar av konvektiva celler. För att finna kunskap om skillnader i intensitet mellan individuella livscykler, har egenskaper som medel och minimum temperatur analyserats. Dessutom har andelen moln med extremt låg temperatur studerats i syfte att kunna använda dessa parametrar som intensitetsindikatorer vid satellitbildsanalys. Resultaten i denna studie visar att de mest intensiva konvektiva molnsystemen (kraftigaste åskvädren), förekommer under påverkan av ITCZ (Inter Tropical Convergence Zone), under antågandet och början av regnperioden. Studier av de konvektiva systemens egenskaper visade att parametrar, som andelen extremt kallt område i molnceller (fractional convective area), och livscyklernas medel och minimum temperaturer, skulle kunna användas som intensitetsindikatorer för att skilja på olika livscykler med avseende på deras styrka i intensitet. Slutsatsen av studien är att det behövs fler studier där andra typer av meteorologiska mätdata, såsom RADAR/LIDAR och sonderingsdata är involverade, för att skaffa ytterligare kunskap om hur man genom satellitbildsanalys kan urskilja kraftiga åskväder.

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