Atmospheric water vapor is a potent greenhouse gas, and its variations in the upper troposphere and lower stratosphere (UTLS) have important climate impacts. The water vapor budget of tropical cyclones (TCs) and their impact on the UTLS remain understudied. This paper describes high-resolution simulations of TC Ingrid during September 2013 using the Weather Research and Forecasting (WRF) model to calculate the water vapor budget. Using Ingrid as an example provides a better understanding of water vapor transport into the UTLS by TCs, helping to answer a question posed during NASA’s Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling through Regional Surveys (SEAC4RS), specifically whether water vapor transport in TCs hydrates or dehydrates the UTLS. Our WRF simulations of TC Ingrid closely correspond to the National Hurricane Center’s Best Track data. We also evaluate model results of the water vapor budget with in situ airborne data of Ingrid collected during the SEAC4RS mission. Satellite imagery also is used to validate the simulated structure of Ingrid. We show spatial and temporal changes of UTLS water vapor throughout Ingrid's lifecycle to determine whether and how TCs hydrate or dehydrate the UTLS. Results show that TCs do transport large quantities of water vapor into the UTLS, and overshooting deep convection is an especially potent transport method. The paper sheds light on mechanisms that inject water vapor into the UTLS and on the widespread horizontal and vertical transports of water vapor within TCs. / A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the Master of Science. / Fall Semester 2016. / November 22, 2016. / flux, lower stratosphere, transport, tropical cyclone, upper troposphere, water vapor / Includes bibliographical references. / Henry Fuelberg, Professor Directing Thesis; Robert Hart, Committee Member; Vasu Misra, Committee Member; Christopher Holmes, Committee Member.

The question of how and when life originated on t his planet has always been an intriguing one, exceeded perhaps in fascination only by that area of speculation which concerns itself with death and the afterlife . The latter problem has generally been approached along theological lines; the former problem , that of the origin of life, has been widely investigated along scientific lines as well . Indeed, the origin of life has always been one of the fundamental problems of science, and the increasingly sophisticated answers to the problem reflect the increasing potence and applicability of the methods of science.

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This dissertation combines several new observations of the Io sodium cloud to create a consistent picture of the extended Io atmosphere and its interaction with the Jovian plasma torus. I used the LPL echelle spectrograph to obtain three types of high-resolution spectra of the extended sodium cloud at the sodium D-lines (5890, 5896Å). The first class of observations made use of the mutual satellite eclipses of 1985 to probe the density profile of the atmosphere in the range 1.4 to 10 Io radii, a previously unstudied region. The second type of observation examined the sodium emission in Io's immediate vicinity, allowing an accurate measurement of the velocity structure around Io. The final method employed a high-sensitivity detector to study faint jets of high-speed sodium farther out in the extended cloud. The synthesis of these three data sets results in a better understanding of how sodium is distributed about Io as a function of position and velocity. Io's extended atmosphere is composed of many kinematically distinct components. The distribution in space is linked to their characteristic velocities, with low-energy sodium confined near Io and faster atoms (10 to 100 km sec⁻¹) prevalent beyond ∼25 Io radii. The sodium density profile is steep near Io and shallower outside 5.6 Io radii, the effective limit of Io's gravity. The data indicate that the atmosphere is collisionally thick near the surface, but becomes thin by an altitude of ∼700 km. The upper limit of the exobase location is derived from reliable sodium density measurements made during the satellite eclipses. The lower limit is indirectly inferred from the velocity distribution of sodium near Io and the nature of high-speed jets far from Io. The high-speed sodium jets reveal a new type of close interaction between the corotating plasma and Io's atmosphere. The morphology and brightness of the jets require a two-reaction process, in which atmospheric sodium is ionized, accelerated to high speeds, and then charge-exchanges with other sodium atoms. These processes must occur near the atmospheric exobase, indicating that Io's atmosphere is not completely protected from the plasma flow.

A measurement of the stable carbon isotopic composition of atmospheric formaldehyde was undertaken as a means of testing current photochemical theories. Sulfito surfaces were shown to meet the stringent analytical requirements of the project; an extensive characterization of these surfaces was performed for the first time. Models were developed to describe the chemical evolution of the surfaces during sampling. It was established that potassium salts have more favorable properties for an atmospheric collection system than do sodium salts. Considerable selectivity in collection was also demonstrated. A highly selective multistep procedure for the isolation and chemical oxidation of collected formaldehyde was developed expressly for this project. A previously unreported combination of reagents, HgCl₂ and AgClO₄, was used in the final reaction step of the procedure. Through the use of synthetic samples, the method was shown to be isotopically reproducible and highly chemically selective. The first data for the carbon-13 content of atmospheric formaldehyde have been obtained, with an observed mean value of δ¹³C = -17‰. This value is enriched in carbon-13 over the known atmospheric sources of formaldehyde; isotopic fractionation in the atmosphere is therefore indicated. It is believed that fractionation due to photolysis can account for the observed effect.

Continuous event-based rainfall samples were collected at three sites throughout the Pensacola airshed from 2005 - 2011. Samples were analyzed for total mercury (Hg), a suite of trace metals (TMs), and major ions in order to understand how thunderstorms affected their wet deposition and concentrations in rainfall, estimate the contributions from regional coal combustion and other anthropogenic sources to Hg and TMs in rainfall along the Gulf Coast, and investigate the possible influence that a local 950 megawatt coal-fired power plant had on rainfall chemistry in the Pensacola airshed. Mercury was measured with a Tekran 2600 using a method that was a variation of the standard method used by the US Environmental Protection Agency (EPA) to measure total Hg in water which allowed for the analysis of TMs from the same bottle without having to worry about contamination from reagents during sample preparation. Trace metals were measured used an Agilent 7500cs quadrupole inductively coupled plasma mass spectrometer (ICP-MS) while utilizing an octopole reaction cell (ORC) which allowed for the detection of key coal-combustion tracers like arsenic (As) and selenium (Se). Our findings show that summertime rainfall Hg concentrations are higher compared to other months despite higher rainfall amounts. In contrast, other measured pollutant TMs and ions did not show a consistent seasonal pattern. By incorporating Automated Surface Observing System data from nearby Pensacola International Airport and WSR-88D radar data from Eglin Air Force Base, we were able to classify the storm type (thunderstorms or non-thunderstorms) and analyze altitudes of hydrometeor formation for individual rain events. This showed that mid-altitude and high-altitude composite reflectivity radar values were higher for both thunderstorm and non-thunderstorm ”warm season” (May - Sept) rain events compared to ”cool season” (Oct - Apr) events including cool season thunderstorms. Thus, warm season events can scavenge more soluble reactive gaseous Hg from the free troposphere. Two separate multiple linear regression analyses were conducted on log-transformed data using interaction and non-interaction terms to understand the relationship between precipitation depth, season, and storm-type on sample concentrations. The regressions without interaction terms showed that the washout coefficients for more volatile TMs like Hg and Se were less pronounced compared to other pollution-type elements and that their concentrations were therefore less diluted for a given increase in precipitation depth, but otherwise displayed similar coefficients for season and storm-type. The regression model with interaction terms revealed a more interesting dynamic where thunderstorms caused enhanced Hg concentrations in rainfall regardless of season or precipitation depth while showing a more volume-dependent relationship with TM concentrations as concentrations increased with increasing rainfall amounts relative to non-thunderstorm events. This suggests a vacuum cleaner effect such that for increasing storm strength, non-Hg aerosol TMs in the boundary layer are further entrained into a storm cell. With this understanding, a positive matrix factorization (PMF) analysis was conducted using the EPA PMF 5.0 software to estimate the contribution of different sources to Hg deposition. Our results suggest that approximately 84% (72 - 89%; 95% CI) of Hg in rainfall along the northern Gulf of Mexico is due to long-range transport from distant sources while a negligible amount (0 - 21%; 95% CI) comes from regional coal combustion. However, we found that anthropogenic sources like regional coal combustion and ore smelting were significant contributors to rainfall concentrations of other pollution-type TMs like copper, zinc, As, Se, and non-sea salt SO42-. Using modeled wind profiles via the HYSPLIT trajectory model, we assessed whether plumes from a local coal-fired power plant (”Plant Crist”) could be detected in the rainfall chemistry of rain events occurring downwind of the plant. We limit this analysis to cool season rain events between June 2007 (when the model began) and December 2011 (when the study ended) because modeled wind profiles showed better agreement with observations during this time period compared to the warm season. We also limit this analysis to cool season events since the spatial distribution of rainfall throughout the area is more even during this time which makes sample comparisons between sites easier since Hg/TM concentrations are affected by precipitation depth. Furthermore, we focus on Hg and other pollution-type TMs and major ions such as As, Se, and non-sea salt SO42- in this analysis as they serve as tracers of coal combustion. For our ”unpaired-site” analysis, we analyzed, for each individual site, the rainfall chemistry in a given sample as a function of the proportion of rain events associated with that sample that occurred downwind of Plant Crist. Using this method, we were not able to find evidence that the plant had a significant influence on Hg/TM concentrations or Hg/TM:Al enrichment ratios in rainfall. Similarly, for our ”paired-site” analysis, we consider the differences in rainfall chemistry between two sites - an upwind and downwind site pair - that were impacted by the same rain event where the downwind site was exposed to plumes from Plant Crist while the upwind site was not. As with the unpaired-site analysis, we did not find significant differences in the rainfall chemistry between upwind-downwind site pairs with regards to sample concentrations or enrichment ratios. A multiple linear regression analysis was then conducted using interaction terms to understand the relationship between the operation of a wet flue-gas desulfurization system (which began operation at the plant during the middle of the study), the relative exposure a rainfall sample had to the plumes coming from the plant, and the log-transformed precipitation depth on log-transformed sample concentrations. Besides for As, the first regression analysis did not find coefficient values of any statistical significance for any of the variables that would indicate that the scrubber affected the rainfall chemistry at the two urban sites nearest to the plant. The calculations for As gave mixed results as the coefficients for the non-interaction terms suggested that the scrubber and the plumes emanating from Plant Crist affected the concentration of As in rainfall while the interaction terms suggested that they did not. We perform another multiple linear regression analysis, but remove the complicating effects of precipitation depth on Hg/TM concentrations and instead analyze the effects that the scrubber and the plumes coming from the plant might have had on Hg/TM:Al ratios. Again, these results were inconclusive as the regression coefficients suggested that the scrubber helped reduce Hg and TM emissions from the plant while also suggesting that samples with more exposure to the plant’s plumes had lower enrichment ratios. We propose that we were unable to detect a chemical signal from Plant Crist in our rain samples due to a few possible reasons including quick scavenging of TMs from the plume at the onset of a rain event before reaching our sites, the reliance on radar data to determine start and stop times for rain events at the sites as opposed to on-site measurements, and relatively low spatiotemporal resolution for the wind trajectory model. / A Dissertation submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / July 16, 2018. / Coal combustion, Mercury, Source-apportionment, Thunderstorms, Trace metals, Trajectory analyis / Includes bibliographical references. / William M. Landing, Professor Directing Dissertation; Thomas E. Miller, University Representative; Christopher D. Holmes, Committee Member; Henry E. Fuelberg, Committee Member; Vincent J. M. Salters, Committee Member.

Ambient particulate matter samples were collected at various sites in Texas, Arizona, and Austria from 2005 to 2009 to characterize the organic compositions and local PM sources. The primary biologically derived carbon sources, specifically the atmospheric entrainment of soil and associated biota and primary biological aerosol particles (PBAPs), are major sources contributing to ambient PM. This dissertation work proposes simple saccharides as well-suited tracers to characterize the contribution to ambient PM from these primary biologically derived carbon sources. Saccharide concentrations in ambient PM were determined from various locations and various seasons. Aerosol saccharide compounds displayed seasonal variations, inter-correlations, and size fractionations (fine vs. coarse) that were consistent between samples and that can be used to determine sources. The difference in aerosol saccharide concentrations and relative species abundances was reflective of different climate patterns and ecosystems. Selected saccharide compounds including an established marker (levoglucosan) and novel markers (glucose, sucrose, trehalose, mannitol, and arabitol) were used along with other markers to model the major source contributions to ambient PM using a positive matrix factorization (PMF) model. Major local PM sources were resolved at three Texas sites (San Augustine, Dallas, and Big Bend National Park) and one Arizona site (Higley), with two source factors enriched in the proposed novel saccharide markers that can be related to the primary biologically derived carbon sources. The contribution to PM from the saccharide-rich primary biological sources was estimated to range from 16% (remote area) to 36% (rural and suburban area) at the four sampling sites studied. Other PM sources identified by PMF included motor vehicles, secondary aerosol formation, meat cooking, biogenic wax, sea salt, crustal material, and road dust. To further characterize the primary biologically derived carbon sources, different soil and source samples representing PBAPs (plants and spores) were collected at Higley (AZ) to study their saccharide compositions in particle sizes equivalent to PM2.5 and PM10. It was found that the total measured non-levoglucosan saccharide content relative to PM mass in ambient aerosols (0.2% on average in PM2.5 and 0.11% in PM10) was much higher than the soil samples (<0.02% in both PM2.5 and PM10) but much lower than in the PBAP source samples (2% on average in plant PBAP samples and 16% in spore PBAP samples). The measured PBAP samples contained a concentration of sucrose and glucose that is consistent with the saccharide-rich source profiles resolved from ambient aerosol data analyzed by PMF while the measured soil samples did not. This can be interpreted as confirmation that PBAPs are an important PM source in additional to soil and associate biota at Higley, AZ. However, the saccharide levels in the measured PBAP samples were several orders of magnitude higher than the PMF results, suggesting that the ambient aerosol samples are a combination of high saccharide concentration PBAPs and lower saccharide concentration soils at Higley, AZ.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Oceanography." Includes bibliographical references (p. 116-133).