Thesis (M. Sc.(Meteorology)) -- University of Pretoria, 2000. / Includes summary. Includes bibliographical references

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Earth & Space Science. / Typescript. Includes bibliographical references (leaves 102-103). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29611

Thesis (M.S.)--Naval Postgraduate School, 1976. / Includes bibliographical references (leaves 141-142).

Thesis (Ph. D.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 10, 2009) Vita. Includes bibliographical references.

Glaciers of southwestern Yukon (Canada) and southeastern Alaska (USA) are presently experiencing high rates of annual mass loss. These high melt rates have mainly been investigated with respect to regional temperature trends, but comparatively little is known about how climate variations regulate snow accumulation on these glaciers. This study examines the synoptic weather patterns and air flow trajectories associated with extreme snowfall events in the central St. Elias Mountains (Yukon). The analyses are based on data retrieved from an automated weather station (AWS) between 2003 and 2012, which provide the longest continuous records of surface meteorological data ever obtained from this remote region. The AWS data reveal that 47 extreme snowfall events (> 27 cm per 12 hours) occurred during this period, of which 79 % took place during the cold season months. Air flow trajectories associated with these events indicate that a vast majority had their origin in the North Pacific south of 50°N. Less frequent were air masses with a source in the Aleutian Arc/Bering Sea region and the Gulf of Alaska, and in a few rare cases precipitating air was traced to continental source regions in Western Canada and Alaska. Composite maps of sea-level pressure and upper-level winds associated with extreme snowfall events revealed a frequent synoptic pattern with a low-pressure area centered over the Kenai Peninsula (Alaska), which drives strong southerly winds over the Gulf of Alaska towards the St. Elias Mountains. This pattern is consistent with AWS data wind recordings during snow storms. The most typical synoptic configurations of the North Pacific low-pressure area during extreme snowfall events are either elongated, split, or single-centered, and these situations represent possible seasonal analogues for the different states of the Aleutian Low in the subarctic North Pacific. However, neither the geographical position or intensity of negative sea-level pressure anomalies, nor surface pressure gradients associated with extreme snowfall events are good predictors of the actual snowfall SWE amounts recorded in the central St. Elias Mountains. Estimated snowfall and total precipitation gradients with altitude were confirmed to be much steeper (by up to ~30 %) on the continental side (Yukon), than on the coastal side (Alaska) of the St. Elias Mountains, reflecting the strong orographic division between the continental and coastal marine climatic regimes. Finally, patterns of 500-mb geopotential height anomalies associated with extreme snowfall events at Divide were compared with those associated with unusually high accumulation years in an ice core from the nearby Eclipse Icefield. Results confirm previous findings that associate high snow accumulation winters in this region with the presence of a strong dipole pressure structure between western North America and the Aleutian Low region, a structure which resembles the positive phase of the Pacific North American atmospheric circulation pattern. / De höga smälthastigheter som uppmätts på glaciärer i S:t Eliasbergen (Yukon, Kanada) har främst undersökts utifrån regionala temperatureffekter, men hur storskaliga (synoptiska) klimatvariationer reglerar snöackumulation på dessa glaciärer är mindre känt. Denna analys belyser synoptiska mönster och rekonstruerade banor av luftmassor i samband med extrema snöfall i den centrala delen av S:tEliasbergen. De iakttagelser som gjorts i denna studie bygger på data som hämtas från automatiserade väderstationer (AWS) mellan 2003 och 2012, vilka ger den längst sammanhängande dokumentationen av markmeteorologisk data som någonsin erhållits från denna plats.AWS data avslöjar att 47 extrema snöfall (>27 cm per 12 timmar) inträffade på glaciären under denna period, varav 79 % ägde rum under den kalla årstiden. I samband med dessa snöfall visar det sig att en stor majoritet av luftmassebanorna hade en utgångspunkt i norra Stilla havet söder om 50°N. Mindre vanligt var att luftmassor utgick från Aleuterna/Berings hav och Alaskabukten, och i några sällsynta fall spårades luftmassorna till kontinentala utgångspunkter i västra Kanada och Alaska. Luftmassebanorna från norra Stilla havet visade främst syd-nordcykloniska luftflöden, medan luftmassorna från Aleuterna/Berings hav och Alaskabukten indikerade väst-öst cykloniska luftflöden. Sammansatta kartor indikerade ett likartat synoptiskt mönster av ett lågtryckscentrum över Kenaihalvön (Alaska) för dessa tre marina källområden. Lågtrycket drev starka sydliga cykloniska vindar över Alaskabukten mot S:tEliasbergen och detta vindmönster överensstämde med AWS data. De typiska synoptiska situationerna i samband med extrema snöfall kännetecknades antingen av ett långsträckt, ett delat eller ett litet lågtryckscentrum. Dessa kunde kopplas till olika möjliga tillstånd av det Aleutiska lågtrycket i norra Stilla havet. Studien kunde inte bekräfta att lågtryckscentrums geografiska placering, anomalier av havsnivåtryck eller tryckgradienten starkt reglerade de extrema snöfallmängderna uppmätta från AWS data på studieplatsen. De beräknade nederbördsgradienterna bekräftades vara brantare på den kontinentala sidan (Yukon) än på kustsidan (Alaska) av S:tElias-bergen, vilket återspeglade skillnader mellan den kontinentala och den kustnära marina klimatzonen. Slutligen jämfördes avvikande geopotentiella höjdmönster i samband med extrema snöfall med tidigare studieresultat av extrem snöackumulation i isborrkärnor från den intilliggande glaciären Eclipse. Resultaten indikerar att dessa mönster delvis korrelerade till tidigare resultat och bekräftar förekomsten av en liknande dipol-tryckstruktur mellan västra Nordamerika och Aleuterna.

This study investigates the impact of the synoptic-scale flow on the propagation and intensity of the sea breeze front at Eglin Air Force Base. The 925 mb wind direction and speed from the 12 UTC Tallahassee sounding was used to categorize 509 summer days as having an offshore, onshore, or coast parallel synoptic-scale flow regimes. Days with similar synoptic-scale flows were then composited together to create hourly surface analyses for each regime. Sea breeze frontogenesis, location and intensity were analyzed on hourly plots of temperature, winds and frontogenesis. Results indicate that the most intense sea breeze fronts formed under 3-5 1 ms- offshore, 7-9 1 ms- coast parallel easterly, and 3-5 1 ms- coast parallel westerly synoptic-scale flow while the weakest fronts formed under 0-3 1 ms- onshore and coast parallel westerly flow. The inland penetration of the sea breeze front was restricted under offshore flow but propagated through the Eglin Range Complex under onshore flow. The intensity of the sea breeze front was found to be a balance between convergence (frontogenetic) and turbulent mixing (frontolytic). Under onshore flow the sea breeze front formed late in the afternoon when convergence at the front was maximized and turbulent mixing decreased. Under offshore flow, the strongest sea breeze fronts formed early in the afternoon due to strong convergence between offshore and onshore winds and weak turbulent mixing.

No description available.

Addendum inserted onto front end-paper. / Bibliography: p. 261-284. / xv, 284 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Provides a thorough analysis of cut-off low phenomena over Australia by using the VHF radar system, operating at a frequency of 54.1MHz / Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1999

Thesis (M.S.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references. Online version available on the World Wide Web.

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1999. / Addendum inserted onto front end-paper. Bibliography: p. 261-284.