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 51 for “"tropospheric ozone"”.
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Local variation and regional transport of tropospheric ozone over Cape Town
… associated with photochemical pollutants such as tropospheric ozone (O3) and some of its precursors. Previous studies have identified local emission sources and meteorological conditions associated with both the air pollution and the brown haze in Cape Town. However, due to the transport of air …
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Current and future consequences of tropospheric ozone on soybean biochemistry, physiology and yield
Crop losses to the damaging effects of tropospheric ozone in the United States are estimated to cost $1-3 billion annually. One of the world’s most important oilseed crops, soybean (Glycine max [L.] Merr.), is particularly sensitive to O3 with current estimated losses of 8.5-14% depending on …
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Studies of Arctic Tropospheric Ozone Depletion Events Through Buoy-Borne Observations and Laboratory Studies
… destruction of ground-level Arctic ozone in the Arctic occurs at the onset of spring, in concert with polar sunrise. Solar radiation is believed to stimulate a series of reactions that cause the production and release of molecular halogens from frozen, salty surfaces, though this …
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Impacts of Elevated Carbon Dioxide and Tropospheric Ozone on the Growth and Productivity of Trees
… greenhouse gases, carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have this potential through direct alteration of photosynthesis. This thesis aims to provide quantitative estimates of the magnitude of the impact of these gases on tree growth and productivity. Free-Air Concentration …
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Applications of Adjoint Modelling in Chemical Composition: Studies of Tropospheric Ozone at Middle and High Northern Latitudes
Ozone is integral to tropospheric chemistry, and understanding the processes controlling its distribution is important in climate and air pollution contexts. The GEOS-Chem global chemical transport model and its adjoint are used to interpret the impacts of midlatitude precursor emissions and …
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Investigating the Impacts of Meteorology and Long-Range Transport on near Surface and Free Tropospheric Ozone over Texas
Ozone produced photochemically in the atmosphere is important from a regulatory and health standpoint. Efficient control technologies and strategies for ozone precursors over the past 20 years have had a noticeable effect on ozone concentrations in many cities across Texas. Although ozone …
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Studies of Stratospheric and Tropospheric Ozone, NO2, and BrO Using UV-Visible Spectroscopy in the Arctic and at Mid-latitudes
… measurements at PEARL, was used to validate ozone and NO2 measurements from the Atmospheric Chemistry Experiment (ACE) and Optical Spectrograph and InfraRed Imaging System (OSIRIS) satellite instruments. Ozone from all instruments agrees to within 12.0%, while NO2 measurements agree to within …
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Tropospheric Ozone over the Middle East and Its Interannual Variability: An Integrated Analysis with Satellite Observations and a Global Chemical Transport Model
Tropospheric ozone is a major atmospheric pollutant and a greenhouse gas. Nevertheless, many processes influencing its spatio-temporal distribution are still poorly understood, mainly due to the lack of adequate observations. One such region is the Middle East, where ozone measurements are scant. …
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An evaluation of Tennessee's early action compacts to achieve compliance with new ozone standards: a dynamic analysis of reduction strategies to decrease tropospheric ozone formation
… Quality Standards (NAAQS) set for ground-level ozone. Under the Compact, local areas will have the flexibility to design and implement ozone reduction control measures specific to the area's needs. The EAC will also defer nonattainment designation from April 15, 2004 to a date no later than …
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A global study of tropospheric methane chemistry and emissions
… loss in the atmosphere, methane also influences tropospheric ozone concentrations, a major air polluter. Experiments have been performed with a chemistry-climate model investigating the effects of source and sink changes on atmospheric methane in a present day (2000) and future (2100) climate. …
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The Economics Of Gasoline Regulation: Price Impacts And Consumer Costs Of Environmental Air Quality Programs
… of two gasoline regulations designed to combat tropospheric ozone pollution. I construct several fixed effects econometric models to assess impacts of reformulated gasoline and low volatility gasoline on retail gasoline prices and consumer costs. I estimate that reformulated gasoline has had a …
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Global heat balance without and with solar radiation management
… perturbs the concentration of CO2, CH4, N2O, tropospheric ozone, other greenhouse gases, and contrails in the atmosphere. Also, anthropogenic influences on short wavelength radiation including effects of land use changes on albedo, anthropogenic tropospheric aerosols and stratospheric ozone …
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Laboratory studies on the production of alpha-pinene-derived organic nitrates and their atmospheric fate
… uncertain, negatively impacting our knowledge on tropospheric ozone production and the fate of atmospheric NO<sub>x</sub>. To lower this uncertainty, we quantified the organic nitrate yield from the OH radical oxidation of α-pinene under high NO<sub>x</sub> conditions. The α-pinene- derived …
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Quantifying the impacts of ozone pollution on the sustainability of pasture
Tropospheric ozone (O3) is a potent threat to food security. In recent years, increasing evidence suggests that ozone can have large effects on the growth and functioning of grassland species, although the responses of grassland to ozone are complex and difficult to predict. Given the global …
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Studies of Arctic halogen chemistry from the snowpack to the gas phase
<p>The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been …
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Halogen Oxide Studies in the Boundary Layer by Multi Axis Differential Optical Absorption Spectroscopy and Active Longpath-DOAS
… the troposphere is due to their strong effect on tropospheric ozone levels, which has been first discovered during surface ozone depletion episodes in the polar boundary layer after polar sunrise (bromine oxide, BrO). Halogen oxides have also been reported from mid-latitude coastal sites (iodine …
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