Where there is water, there can be life. Improving our understanding of how life, as we know it, arose uniquely in our solar system on Earth depends critically on our understanding of the history of water in the solar system. Better characterizing the sources of water to the Earth-Moon system is crucial in constraining this history and motivated the experiments described in this dissertation.

The oxygen isotopic composition of water in lunar samples in addition to meteorites from Mars and several asteroids, which have delivered significant material to the Earth-Moon system, were characterized. The ordinary chondrite (OC) samples, Bjurböle matrix, Bjurböle chondrules, and ALHA77216, contain 17O-enriched water with, Δ17O up to 1.5‰, released by high temperature heating. Water liberated from the carbonaceous chondrite (CC), Murchison, by heating to high temperatures (≤ 1000˚C) possess Δ17O approaching -1.5‰. Low-temperature fractions of water from these OC and CC samples is mass-dependently fractionated (Δ17O ≅ 0‰). The eucrite, PCA 91006 releases water upon heating to 50-350˚C with Δ17O ≅ 1‰ and 600-1000˚C with as low as -11‰. The martian meteorite, NWA 7034, contains water with an average Δ17O = 0.32‰. The lunar samples analyzed (10049, 10057, 10060, 12021, 12039, 14163, 14305, 79035) possess water with average Δ17O = 0.18‰. The oxygen isotopic composition of a whole rock sample of a carbonaceous chondrite (CC) meteorite, Sutter’s Mill, was also measured, and possesses Δ17O = -1.8‰. The 1σ error on these Δ17O values is 0.011‰. These results reveal that delivery of water by OCs and CCs could account for almost all of the lunar water isotopic compositions measured.

Complementary studies measuring the isotopic composition of ozone (O3), an important precursor to water, formed in experiments performed under analogous conditions to those that existed early in the formation of the solar system were also conducted. Additionally, experiments characterizing the isotopic composition of O2 involved in ion-molecule reactions which dominate molecule-formation processes occurring in cold regions of interstellar molecular clouds were also conducted. These complementary studies help define and explain the isotopic composition of oxygen-bearing reservoirs, especially water, in the present-day inner solar system.

Sulfur, the 10th most abundance element in the universe, has variable valence states (from -2 to +6) and therefore actively participates in a host of biogeochemical processes in nature. Since the earliest geological record of the primitive Earth, sulfur has been ubiquitous and has played an important role in the evolution of life and the ability to track its origin. In the present-day Earth, interest in the terrestrial sulfur cycle predominantly stems from anthropogenic influences on the atmospheric sulfur budget and the key role of sulfate in affecting climate. To understand a wide range of physical, chemical, and biological processes involved in the aforementioned topics, measurements of quadruple stable sulfur isotopes (32S, 33S, 34S, and 36S) in terrestrial samples (e.g., rocks, ice cores, aerosols) have been utilized. However, cosmogenic 35S, the only radioactive sulfur isotope with an ideal half-life (~87 days) for tracking atmospheric, hydrological, and biogeochemical processes, is seldom measured because of its low-energy decay, low abundance in nature, and associated analytical difficulties. In this dissertation, new analytical techniques were developed for accurate quantification of 35S in atmospheric, cryospheric, and hydrospheric samples using an ultra-low-level liquid scintillation spectrometer (chapters 2 and 3). Based on these newly developed analytical methods, I measured 35S in varying natural samples collected around the Northern Hemisphere to explore the use of 35S in the Earth, atmospheric, and planetary sciences. I demonstated that 35S is a highly sensitive tracer for quantifying the downward transport of high-altitude air masses and gas-to-particle conversion rates of sulfur in the terrestrial atmosphere, and provided new insights into atmospheric vertical mixing (from the boundary layer to stratosphere) and sulfur chemistry over the Pacific Rim, Himalayas and Tibetan Plateau (chapters 4-8). Using simultaneous measurements of all five sulfur isotopes (32S, 33S, 34S, 35S, and 36S) in the same sulfate aerosol samples, I discovered two distinct mass-independent sulfur isotope effects in the present-day atmosphere, which points to previously unrecognized areas for understanding the fundamental chemical physics of sulfur isotopic mass-independent fractionation and the earliest sulfur cycle on Earth during the appearance and evolution of early life (chapters 9 and 10).

Atmospheric aerosols remain the largest uncertainty in assessments of the anthropogenic influence on Earth’s radiative budget. Aerosols affect Earth’s radiative budget directly, by reflecting and absorbing incoming solar radiation, and indirectly, by serving as nuclei for water and ice cloud formation. Current estimates of anthropogenic impacts on the direct and indirect aerosol effects are hindered by an inadequate understanding of how naturally produced aerosols contribute to both processes. Sea spray aerosol (SSA), formed by oceanic wave breaking, represents the largest source of natural aerosol to the atmosphere by mass. The climate-relevant properties of SSA, such as hygroscopicity, reflectivity, and ice nucleation ability, are highly dependent on the amount and composition of the organic material transferred from the seawater into these aerosols. The composition of this organic material is strongly influenced by microbial activity in the seawater, highlighting the importance of employing new techniques to examine the impact of oceanic biological activity on the organic material transferred into SSA. Carbon isotopic analysis has been frequently employed to differentiate between anthropogenic and natural sources of aerosol carbon, but has not previously been applied to study ocean-aerosol transfer of organic material. In my dissertation work, I measured carbon isotopic compositions (d13C) of seawater and SSA organic material during two laboratory phytoplankton blooms, identifying an increased contribution of “freshly-produced” carbon to SSA, strongly controlled by the microbial loop. I further demonstrate that not accounting for this biological influence on the d13C value of nascent SSA can lead to significant underestimates in the contribution of anthropogenic aerosol carbon to the marine environment (Chapter 2). Building from this work, I investigated differences between submicron and supermicron SSA during a wave channel mesocosm experiment. The stark differences between these two SSA fractions, with supermicron SSA heavily influenced by biological activity and submicron SSA primarily influenced by surface-active anthropogenic compounds originating from the coastal seawater, reveals the importance of biology and ocean-aerosol transfer processes on SSA organic composition and d13C (Chapter 3). Finally, I explored biologically induced changes in seawater submicron particulates (SMPs) in the bulk seawater and SSML to better understand how seawater biology may influence the transfer of ice nucleating entities into SSA (Chapter 4).