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 18 of 18 for “"Back Trajectories"”.
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Chemical composition and pH of marine aerosols in the summer-time marine boundary layer of the Atlantic sector of the Southern Ocean
… sea ice concentration data, along with air mass back trajectories, it was found that generally, aerosol samples that originated from the open ocean were relatively more acidic compared to those that had air mass back trajectories originating from sea ice covered surface ocean. This was attributed …
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The influence of the Agulhas Current on two South African extreme weather events
… tornadoes were reported in the Umtata and Hogsback regions of the Eastern Cape. Both storms appeared to result from interaction between a continental heat low, advection of warm moist air around an anticyclone in the South-west Indian Ocean and an approaching midlevel westerly trough. NCEP …
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Natural variability in eastern tropical Pacific nitrous oxide emissions
… around the Pacific Ocean were combined with back-trajectories calculated using the HYSPLIT4 atmospheric model, in order to study the relative importance of OMZs on Pacific N2O emissions. Spatial and temporal variability in nitrous oxide concentrations were analyzed in order to determine …
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Investigating the Use of Fallout Radionuclides Beryllium-7 and Excess Lead-210 as Short-Term Stream Sediment Chronometers in the Agricultural Upper Midwest, USA
… Trajectory (HYSPLIT) model to trace the back trajectories for storm series for which the beryllium-7 and lead-210 activities of precipitation were measured. I used this analysis to fill knowledge gaps that affect the sediment aging technique I employed in my first chapter.
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Source air feeding convection within a nocturnal mesoscale convective system during the evolution from surface-based to elevated convection
… Research and Forecasting (WRF) model, and back trajectories produced by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. This paper describes the evolution of the boundary layer as well as the spatial and temporal progression of the altitude of the most unstable …
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Tracking Potential Sources of Peak Ozone Concentrations in the Arabian Gulf Region
… Particle Lagrangian Integrated Trajectory Model) back trajectories using these coordinates as a starting point were run to trace the origins of the air mass up to 3 days prior. World Wide Lightning Location Network (WWLLN) lightning data for the northern hemisphere in August and National Oceanic …
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Chemistry of the sea ice/ snowpack/ atmosphere system in coastal Antarctica
… such events, ozone concentrations can fall from background amounts to below instrumental detection limits within a few minutes and remain suppressed for on the order of hours to days. The chemical destruction of ozone is driven by halogens (especially bromine radicals) that have a source …
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Supermicron-size aerosol particles originating from biomass burning in south-central Africa
… Integrated Trajectory) models for three-day back trajectories show a source location in northern Angola for the time periods when large SAPs were observed. FIRMS (Fire Information for Resource Management System) MODIS 6 (Moderate Resolution Imaging Spectroradiometer) active fire maps showed …
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Structure of an east coast cyclone derived from airborne radar and model diagnostics
… (WRF) Model thermodynamic fields and air-parcel back trajectories from the HYSPLIT model are used to determine causes of finescale features of a northeast U.S. cyclone and link them to synoptic and air mass structure. The storm intensified and propagated along the New England coastline on 2 …
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Trace metal applications in atmospheric and watershed dynamics: Case studies of mercury deposition in New England and bedrock groundwater-surface water mixing
… The analytical results coupled with air mass back trajectories suggest that the greatest amount of Hg wet deposition occurs when polluted continental air mixes with marine air.</p><p>A new filter extraction method for determining the environmentally mobile Hg concentration in bulk aerosol …
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Glaciochemical records from the Saint Elias Mountains, Yukon, Canada
… of gas phase nitric and hydrochloric acid. Back trajectories document the transport of Asian dust and anthropogenic emissions, the May 22 eruption plume of Sheveluch, Kamchatka, and sea salt from the Gulf of Alaska to King Col during the sampling period. The Eclipse ice cores provide a …
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Polar föhn winds and warming over the Larsen C Ice Shelf, Antarctica
… are quantified using a novel method analysing back trajectories and MetUM 1.5 km model output. It is shown that, depending on the linearity of the flow regime and the humidity of the air mass, each mechanism can dominate. This implies that there is no dominant foehn warming mechanism, contrary …
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The natural and industrial cycling of indium in the environment
… geographically and temporally. Atmospheric back trajectories, correlation of indium to other metals in these samples, and receptor modeling suggest that the highest indium concentrations come from nonferrous smelters in the north, while lower concentrations are seen in air traveling from the …
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Aerosol chemistry and air-snow transfer in coastal Antarctica
… appear to have a local source. Instead, using back trajectories of air mass origins to identify a longer range aerosol source, high concentration events were associated with the air mass having passed over an area of open water several days before reaching Halley.<br></br><br></br>The processes …
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Variations of the chemical characteristics and source regions of aerosols at the Cape Point GAW station
… influence on samples is evaluated. Air mass back trajectories and radon (222Rn) concentrations were used to classify the air masses of each aerosol sample as either marine, modified marine, or continental. We found that continental samples had elevated concentrations of NH4 + , NO3 - , and …
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Characterisation of air masses passing over the Vredefort Dome world heritage site
… some limitations, since the frequency of such back trajectories was limited and those that did comply passed mostly over the cleaner south-western sector from the Vredefort Dome. Additionally, dilution during transport and aging of air masses after passing over the Vredefort Dome before …
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Characterizing the influence of anthropogenic emissions and transport variability on sulfate aerosol concentrations at Mauna Loa Observatory
… continental tracer concentrations and HYSPLIT back trajectories suggests that non-negligible long distance influence from either the Asian or North American continents can be detected at MLO during all seasons although large interannual variability was observed. Possible influence of …
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Characterisation of Microphysical and Optical Properties of Atmospheric Aerosols in a High Arctic environment: Villum Research Station, NE Greenland
Atmospheric aerosols are solid or liquid phase particles which are suspended in ambient air. These particles have an impact on the climate through direct and indirect radiative forcing, and their measurement presents challenges in high latitude environments where concentrations may fall under the …