Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [135]-144).

Thesis (Ph. D.)--University of California, San Diego, 1998. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (p. [286]-301).

Thesis (Ph. D.) -- California Institute of Technology, 2010. / Title from home page (viewed 03/19/2010). Advisor and committee chair names found in the thesis' metadata record in the digital repository. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvii, 142 p. : ill. (some col.). Advisor: Terry A. Miller, Department of Chemistry. Includes bibliographical references (p. 133-142).

Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [189]-196).

Thesis (Ph. D., Chemistry)--University of California, Irvine, 1990.

Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2007. / Dr. Greg Huey, Committee Chair ; Dr. Paul Wine, Committee Member ; Dr. Rodney Weber, Committee Member ; Dr. David Tan, Committee Member ; Dr. Robert Whetten, Committee Member.

The literature on acid rain provides evidence that large (>5 μm) alkaline particles in the atmosphere, which derived from surface soil, play an important role in mitigating the effect of acid rain. Not only do they help to neutralize acidity but they also are a source of nutrients to the terrestrial and aquatic environments. While ground-up limestone has been added to the forests and the lakes of regions deficient in alkalinity, this mode of application is prohibitively expensive. An economic alternative method of distribution would utilize the advective and turbulent diffusive processes within the troposhere in order to supply limestone particles of approximately 10 μm diameter to the terrestrial and the aquatic environments. However, while the particles are being transported through the atmosphere they will also interact to some degree with the atmospheric pollutants (SO₂, NOx, photochemical oxidants, etc.). While the two-phase chemical interaction of water droplets and gaseous pollutants has been extensively studied, little is known about the reaction between limestone particles and gaseous pollutants under ambient conditions. As a first step in understanding these processes laboratory experiments were conducted in order to measure the rate of the heterogeneous reaction between limestone particles and sulphur dioxide (SO₂) gas in clean humid air. Calcitic limestone (200-270 mesh Tyler) from Texada Island, B.C., was reacted with 30-80 ppb SO₂ at room temperature (17-22°C) over a humidity range of 70-100%. Ancillary experiments were also conducted to determine the maximum dissolution rate of these limestone particles in an acidic, aqueous environment. The overall rate (r) for the SO₂ reaction with Texada Island limestone was determined to be approximately first-order with respect to the SO₂ concentration and to be strongly dependent upon the relative humidity: [Formula Omitted] Limited experiments with precipitated dolomite indicated that it reacts with SO₂ somewhat faster than does the calcitic limestone. A study of the individual mass transfer and reaction processes indicated that the rate limiting step for the overall reaction was the aqueous phase oxidation of the bisulphite ion. Limestone dissolution (determined experimentally), and estimated gas and aqueous phase diffusive processes, were not rate limiting. In a clean humid atmosphere, free of photochemical oxidants, a limestone aerosol would react very slowly with SO₂ (SO₂ removal rate of about 3x10⁻³% per hour). However, in a humid polluted atmosphere rich in photochemical oxidants, similar to that responsible for acid fog and acid rain, the aqueous phase oxidation of dissolved SO₂ is not expected to be rate limiting. Under such conditions bisulphite dissociation: [Formula Omitted] Therefore in humid, polluted atmospheres limestone aerosol will act as a "sink." for SO₂ for soluble photochemical oxidants, and probably also for HNO₃ (nitric acid). Since the oxidants are considered to be phytotoxic while the other pollutants are responsible for creating acid rain we conclude that the deployment of a limestone aerosol may have a positive impact on the atmospheric environment, besides being beneficial to the aquatic and terrestrial environments. It is strongly recommended that further research be done in this area in order to better quantify the rate processes, and perhaps also to identify practical methods for increasing the atmospheric concentration of alkaline aerosol in those geographic regions which are deficient. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Atmosphere-biosphere exchange plays a key role in the global cycles of water and carbon. Air pollution can alter these processes and induce climate perturbations and feedbacks. Surface ozone (O3) is an air pollutant and greenhouse gas that is toxic to plants, reducing their growth and ability to regulate water loss. Past controlled experiments have shown that O3 degrades a plant's water-use efficiency (WUE), which is the ratio of carbon uptake in photosynthesis to water loss in transpiration. This has potentially significant implications for terrestrial water cycle and precipitation, but no studies have evaluated the O3 effect on WUE in complete ecosystems. We aim to quantify the impact of O3 on WUE across a wide array of ecosystems. Meteorological and biological data was obtained from 23 FLUXNET flux tower sites, which use the eddy covariance method to derive hourly fluxes of carbon dioxide (CO2), water vapor (H2O), and O3 between the atmosphere and ecosystem. Across a broad range of sites, we find a significant negative relationship between daily anomalies of stomatal O3 flux (FS, O3) and WUE that explains 1-3% of WUE variability. The largest impacts occur in locations and species with high stomatal conductance, such as broadleaf forests, humid climates, or irrigated crops, rather than where surface O3 concentrations are highest. Past long-term studies have also found similar O3 impacts (1-3%) on WUE, indicating a consistent response across a pool species and ecosystems. / A Thesis submitted to the Department of Earth, Ocean, & Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester 2016. / March 23, 2016. / Ecosystems, FLUXNET, Natural environments, Stomatal ozone flux, Water-use efficiency / Includes bibliographical references. / Christopher D. Holmes, Professor Directing Thesis; Stephanie Pau, Committee Member; Vasu Misra, Committee Member; Jon Ahlquist, Committee Member.