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 77 for “"Trace Gases"”.
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Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica
… (70°S, 8°W). The measurements of the atmospheric trace gases ozone, NO2, OClO, BrO, IO and O4 were performed using a new UV/Vis spectrograph, developed within the scope of this work. The main intention of DOAS measurements in the Antarctic coastal region was to investigate the chemical composition …
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Transport Processes of Reactive Trace Gases in the Atmospheric Boundary Layer
Transport of trace gases within the atmospheric boundary layer plays a key role in feedback processes between the earth’s surface and the atmosphere and consequently in ecosystem budgets of carbon and nitrogen (among many more). For a correct quantification of the exchange between surface and …
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Imaging of volcanic trace gases by Fabry-Perot interferometer correlation spectroscopy
Imaging of atmospheric trace gas distributions by optical remote sensing allows for a direct assessment of the dynamics of both physical and chemical processes. In particular, the fast evolution of trace gases emitted by point sources (e.g., volcanic plumes) can be studied comprehensively by …
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Optimal determination of global tropospheric OH concentrations using multiple trace gases
… path of removal for a variety of greenhouse gases and trace species that contribute to the destruction of the ozone layer. Accurate determination of global tropospheric OH concentrations [OH] is therefore a very important issue. Previous research at the global scale has focused on scaling …
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Exchange of radiatively active trace gases in tundra environments, with particular attention to methane
This thesis is concerned with trace gas flux in tundra environments, the main subject of study being methane. Methane emission from tundra soils has in recent years attracted increasing attention due to the possible associated feed-back effect on man-made climate change. The presented data are …
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Reactive Trace Gases within and above a Grassland Canopy: Challenges for Flux and Transport Process Determination
… (NO2) and ozone (O3) constitute a reactive trace gas triad, which is highly important for the oxidizing capacity of the atmosphere, the functioning of ecosystems and climate change. Terrestrial ecosystems, such as grasslands, represent considerable sources and sinks for the NO-NO2-O3 triad …
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Measurements of Reactive Trace Gases and Variable Ozone Formation Rates in South Carolina Biomass Burning Plumes
… burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. BB trace gases and particles are of both regional and global importance. In the US, prescribed fire and wildfire are the two major fire types and …
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Measurements of Reactive Trace Gases and Variable Ozone Formation Rates in South Carolina Biomass Burning Plumes
… burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. BB trace gases and particles are of both regional and global importance. In the US, prescribed fire and wildfire are the two major fire types and …
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The effects of elevated CO2 and ocean acidification on the production of marine biogenic trace gases
… culture studies. DMS is a climatically important trace gas produced by marine algae: it transfers sulphur into the atmosphere and is a major influence on biogeochemical climate feedbacks. Halocarbons are also important biogenic trace gases which undergo atmospheric photochemical degradation, …
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Sources and sinks of selected trace gases in the tropospheric boundary layer of the eastern United States
… goal of characterizing sources and sinks of trace gases of strong relevance to regional air quality and global climate issues. In the first study, volatile organic compound (VOC) measurements collected at a marine and continental site in northern New England were compared and examined for …
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Long term trends of halogenated trace gases, hydrocarbons, alkyl nitrates and of the oxidative capacity of the atmosphere
… depleting substances (halons) and greenhouse gases (PFCs, SF5CF3, HFC-227ea) are reported using measurements from Cape Grim, Tasmania. A two-dimensional global atmospheric chemistry transport model is used to derive global annual emission histories of these long lived gases. Emissions of the …
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Trace gases in Antarctic and Greenland firn and ice: a record of carbonyl sulphide and the isotopologues of chlorofluorocarbons
… the industrial revolution of the last 250 years, trace gases have had a significant impact on the climate. Of particular relevance to this work are species which facilitate the destruction of stratospheric ozone. In this thesis, I focus on four of these species. Understanding the release, reaction …
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Retrieval of trace gases vertical profile in the lower atmosphere combining. Differential Optical Absorption Spectroscopy with radiative transfer models
… retrieve profile information for the atmospheric trace constituents nitrogen dioxide (NO2) and ozone (O3) in the lower troposphere from remote sensing measurements. The remote sensing technique used, referred to as Multiple AXis Differential Optical Absorption Spectroscopy (MAX-DOAS), is a recent …
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Physical and chemical characterization of single atmospheric aerosols: Laboratory studies of interactions of acidic trace gases with sea -salt aerosols, and, Development efforts for an aerosol charging system using a corona discharge
… was used to study the interaction between acidic trace gases and artificial sea-salt aerosols in a laboratory environment. The chamber housing the spherical void electrodynamic levitator was designed to simulate conditions found in a polluted marine boundary layer. The reactive uptake coefficient …
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Study of atmospheric carbon monoxide and methane
… widely used for the investigation of atmospheric trace gases. We measured the stable isotopes d13C and dD of atmospheric CH4 as well as d13C, d18O and the 14CO concentrations of atmospheric CO at Izana, Tenerife, from 1996 to 1999. We report the first directly measured dD seasonality for …
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Optimierung der Parameterauswahl für ein operationelles off-line-Retrieval von Spurengasvertikalprofilen aus MIPAS-Daten
… off-line retrieval of vertical profiles of trace gases from MIPAS data”. Since March 2002 the environment satellite ENVISAT is operational. ENVISAT carries a series of instruments used for remote sensing the earth atmosphere. MIPAS, as one of those instruments is, due to its conception as a …
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Fluxes of the NO-O3-NO2 triad above a spruce forest canopy in south-eastern Germany
… in air pollution. Together the three reactive trace gases NO, NO2 and O3 undergo a series of interconnected reactions and are often referred to as the NO-O3-NO2 triad. This triad has attracted attention from scientists in the recent past because of the role that it plays in causing problems …
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Impacts of long-range transport of biomass burning on air quality in Texas.
… ratios of volatile organic compounds (VOCs) and trace gases in major cities in Texas: San Antonio, and Houston, and (2) investigate the physical and chemical properties of transported biomass burning (BB) smoke and their impact on background air quality in Port Aransas, an industrialized coastal …
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