A highly debated research topic has been understanding the magnitude of tropical cooling in the western Pacic warm pool (WPWP) from the Last Glacial Maximum (LGM) to present-day. Paleoclimate data indicates a range of LGM cooling from 1-5°C. Using a radiative-convective model with an entraining plume calculation, the present-day and LGM snowlines can be explained with a 3.5°C surface cooling in the WPWP during the LGM. NCAR's CCSM 3 and 4 simulate LGM cooling of 2°C. By comparing the results of CCSM3 and CCSM4, the higher resolution CCSM4 replicated LGM boundary conditions more accurately, increased LGM precipitation rates 0.4 mm/day, and reduced the transport of drier subtropical air from the Northern Hemisphere into the WPWP. One of the major issues in the CCSM identied in this thesis is the propagation of a temperature signal associated with the boundary layer over mountains to the upper-levels of the troposphere.

The elemental composition of calcium carbonate (CaCO3) precipitated by marine invertebrates varies with the physico-chemical properties of seawater, and is thus used for reconstructing past oceanic conditions, including temperature, pH, and seawater composition. Previous studies have used a Rayleigh fractionation model to interpret elemental partitioning within a range of calcitic and aragonitic organisms. This thesis contains analyses of elemental ratios for multiple marine invertebrates that were cultured from seawater under variable conditions using both new unpublished results and data from the literature. The partitioning of strontium, magnesium, barium, manganese, boron, lithium and uranium within these biogenic carbonates, and data from the literature for foraminifera and coccolithophores, are examined within a Rayleigh fractionation framework.

Application of a Rayleigh model to these systems requires constraints on elemental partitioning into inorganic CaCO3. A survey of the literature shows that for some elements (e.g., Mn), there are very little data, while for others (e.g., Sr, Mg), there are a wide range of reported values. Given this uncertainty, I examine the impact that varying the nominal inorganic partition coefficient has on Rayleigh-derived estimates of calcium-utilization during calcification. The elements examined in this thesis have different chemical and ionic properties (atomic mass, ionic radius, charge), and these properties impact how readily the element can be incorporated into the CaCO3 lattice by replacing its constituents. A Rayleigh model allows one to examine how open the calcification system of an organism is, as well as how much calcium is remaining in the calcification reservoir after biomineralization is complete. I show that organisms that are evolutionarily similar to each other behave similarly in this model, and therefore are likely to use similar mechanisms for biomineralization; for example, organisms from the Crustacea phylum calcify from a relatively closed reservoir with a slow flushing rate, while organisms of the Mollusca phylum calcify from an open calcification pool and have a very fast flushing rate. There are still a few problems with the use of a Rayleigh model in the context of biological calcification; these issues are discussed in-depth throughout the study. An overview of the effects of changing pCO2 and temperature on element partitioning in these invertebrates is examined. I used a combined understanding of organism physiology and Rayleigh fractionation geochemistry to elucidate how certain groups of marine calcifiers control their calcification, and how this control can influence elemental ratios in calcium carbonate that are sometimes used as paleo-proxies.

In the Great Basin, paleoshoreline reconstructions for closed basin lakes indicate that highstands correspond with Pleistocene glacial maxima. Lacustrine deposits at these sites are physically and chemically sensitive to changes in the balance between precipitation and evaporation, which drive lake level fluctuations. However, uncertainties remain regarding the magnitude of temperature change in the region between glacial and interglacial periods. In this thesis, carbonate clumped isotope thermometry is applied to define the parameters of temperature, evaporation, and precipitation at Lake Bonneville. Bonneville was the most expansive lake in the Great Basin during the Last Glacial Maximum (LGM). Multiple phases of carbonate were evaluated, including aragonitic shells of two taxa of lacustrine gastropod, marls, and tufa. Carbonate clumped isotope results of ancient material were calibrated by comparison to measurements of modern lacustrine carbonates at sites, where water temperatures are constrained. Summer water temperatures were estimated from gastropod and marl samples during the LGM, from 23 to 19 ka BP. Tufa and gastropod samples were also analyzed during the Stansbury Oscillation phase of lake history, from 25.8 to 24.5 ka, and the Bonneville Highstand and Provo phases of the lake, from 18 to 14.5 ka. Reconstructed water paleotemperatures were applied to estimate summertime and mean annual air temperatures using lake-atmospheric transfer functions. Warm season (May through September) water temperatures are estimated to be 7.1±0.6ºC lower than present-day values of 18.1 to 19.0ºC in the Bonneville Basin, and 3.1±0.9ºC lower than present-day values of 19.7ºC in the Sevier Subbasin. Annual air temperatures are estimated to be 9.2±0.8ºC lower than present-day values of 8.7 to 9.5ºC in the Bonneville Basin, and 3.3±1.1ºC lower than present-day values of 10.1ºC in the Sevier Subbasin. Clumped isotope temperature reconstructions exceed the PMIP climate model ensemble mean in the Bonneville Basin, but suggest less cooling than the ensemble mean in the Sevier Subbasin. Clumped isotope temperatures are also combined with carbonate oxygen isotope (δ18O) ratios to determine water δ18O associated with mineral precipitation, which tracks evaporative enrichment in lakes. Results indicate that lake water δ18O was above modern precipitation values, but that enrichment of water was less than at the modern Great Salt Lake. Reconstructed evaporation, derived from clumped isotope temperatures, varied from 60 to 83 percent of modern values, while precipitation over the lake was determined to be 75 percent of the modern rate. These results are lower than the PMIP3 ensemble mean, and suggest that Lake Bonneville transgressed, at least initially, as a result of lower evaporation, and not increased precipitation.

A powerful tool for reconstructing past temperatures is based on the extent of carbonate ions in carbonate minerals with more than one heavy isotope substitution, termed carbonate clumped isotopes. The use of the clumped isotope thermometer assumes that the mineral formed under isotopic equilibrium conditions, however, some carbonate minerals can form from dissolved inorganic carbon pools that are not equilibrated. Here, we use dual clumped isotope measurements of mass 47 and mass 48 (13C18O16O - Δ47; 12C18O18O - Δ48) CO2 from gas liberated by acid digestion of carbonate minerals to constrain equilibrium clumped isotope relationships and kinetic isotope effects. In one manuscript, we present results for widely used laboratory standards that lay a strong foundation for the measurement and application of paired Δ47 and Δ48. In a second manuscript, the results from controlled inorganic calcite precipitation experiments constrain kinetic isotope effects in Δ47 and Δ48 from hydration and hydroxylation and compared to theory, and enzymatic effects are studied. Non-linear mixing effects in Δ47 and Δ48 are also determined using experiments and theory. In a third manuscript, we report Δ47 and Δ48 for amorphous calcium magnesium carbonates and transformation products, and show they are distinct from mineral equilibrium. We propose a new mechanism for disequilibrium clumped and oxygen isotope values in carbonate minerals that precipitate from an amorphous calcium carbonate precursor. Results indicate that the dissolution of an amorphous precursor may cause disequilibrium in the dissolved inorganic pool during transformation to a crystalline phase, that can impact final mineral dual clumped isotope and oxygen isotope values.

Lakes are responsive to climate, and in turn, sediment formed within lakes function as recorders of environmental change. This dissertation explores how the clumped and bulk stable isotope geochemistry of lacustrine sediments can be used to understand the terrestrial hydrologic cycle, both in the modern and past. To better understand the modern systematics of clumped isotopes in freshwater carbonates to extend to paleo-applications, Chapter 1 discusses the first extensive calibration study of different types of field-collected carbonates. We examine the uncertainties associated with the use of a single calibration in different types of carbonates, and evaluate relationships for material-specificity, allowing for more robust reconstructions of past temperature and water δ18O reconstructions. In the following three chapters, these calibrations are applied to late-Pleistocene lacustrine sediments from eleven lake basins in Western North America to evaluate multiple hydroclimate parameters, including temperature, water δ18O, evaporation, and precipitation, including for the Last Glacial Maximum (LGM; 23-19 ka) and deglaciation. In Chapter 2, we examine Lake Bonneville, which reached the size of a modern- day Great Lake at its maximum extent, and report the importance of evaporation suppression in setting and sustaining the lake, while also quantifying precipitation, with maxima during the early LGM and Heinrich Stadial 1 (HS1). In Chapter 3, we examine four basins in the Northern Great Basin to quantify the magnitude of evaporation and precipitation variation in the mid- latitudes, and test for a hypothesized precipitation dipole. At the two northernmost sites, we report evidence in support of enhanced evaporation depression and westerly-derived precipitation during the LGM and deglacial, leading to the presence of lakes in the region. We find at the southernmost site evidence for reduced evaporation and evidence for moisture advection into the continental interior from the south (e.g. higher atmospheric river and North American monsoonal precipitation) during the deglacial. In Chapter 4, we evaluate hydroclimatic changes using six basins in Arizona, New Mexico, and Northern Mexico, and find reduced temperatures and evaporation rates with increases in precipitation during the LGM and deglacial. The drivers of LGM and deglacial precipitation vary, with winter-derived precipitation the primary source of high levels of moisture in the Southwestern US, and tropical storms the likely origin of more modest enhancements in Northern Mexico.

We study North American summer monsoon (NASM) and East Asian summer monsoon (EASM) precipitation in modern and glacial climates from the perspective of mid-latitude wave dynamics. The thesis consists of two major parts: the study of summertime North America precipitation change since Last Glacial Maximum (LGM, 21ka), and dynamics of NASM/EASM precipitation in a modern climate. We begin our study by analyzing precipitation data from pollen reconstructed proxies and ERA-Interim reanalysis. We provide physical explanations using models with different levels of complexities including Paleoclimate Model Intercomparison Project (PMIP3), Laboratoire de Meteorologie Dynamique (LMDZ), a simplified GCM [1], and semi-analytical models (the Charney-Eliassen model [2], the Eady model [3] and the two-layer quasi-geostrophic model [4]).

We first study the precipitation dipole, defined as moistening the American Southwest and drying the American Southeast during LGM, which has been identified through paleoproxy reconstructions and tested with climate model simulations. By analyzing the PMIP3 simulations, we suggest that the summertime stationary waves with NW-SE tilting and eastward phase-shifting in LGM enhance precipitation in the American southwest and also dry the American southeast. Numerical experiments performed with the LMDZ model indicate that Laurentide ice topography induces NW-SE tilting and an ice thermodynamic effect triggers eastward phase-shifting of stationary waves. A new solution of the Charney-Eliassen model is derived to quantify that the phase-shifting correlates positively with the strengths of jet streams. By comparing a synthesis of LGM pollen proxies to the PMIP3 ensemble, we nd models that simulate a weaker Laurentide ice thermodynamic effect, weaker stationary waves with greater NW-SE tilting, weaker phase-shifting, and weaker jet stream anomalies compare more favorably to the proxies. Since the thermal wind equation links meridional temperature gradients to vertical wind shear, the weaker summer polar amplification compares more favorably to the proxy.

Secondly, we use a global space-time diagram of column water vapor (CWV) at 30N latitude from daily reanalysis data, and nd two quasi-stationary parts of atmospheric rivers (QSARs) that feature locally enhanced CWV and evolve from the Eastern Pacific/Atlantic

basins in the winter to the Western Pacic/Atlantic in the summer. East Asian Summer Monsoon (EASM) onset coincides with the time CWV in the Pacific QSAR first exceeds 40 mm, which also typically occurs just before it makes landfall. QSARs exist in 39-year (1979-2017) daily climatological CWV, demonstrating the seasonal cycles of these features are quasi-stationary and potentially useful for monsoon onset prediction. EASM onset is particularly predictable following El Ni~no Southern Oscillation (ENSO), consistently occurring

25-40 days after the QSAR crosses the dateline.

Given the fact that atmospheric rivers are lead by mid-latitude synoptic waves generated by baroclinic instability, we then study the dynamics of QSARs using theories of baroclinic instabilities. Simplified GCM experiments are applied to identify that the zonal anomalies

of jet streams induced by the tropical warm pools-cold tongues trigger the formations of the QSAR-like features. Analysis of local wave activity (LWA) reveals QSARs as fronts of wave breakings, and indicates that QSARs are likely to be quasi-stationary baroclinic waves. These quasi-stationary baroclinic waves could be predicted semi-analytically by applying the Eady and the two-layer quasi-geostrophic models, thus opening a new window into dynamics of subtropical monsoon extensions.

Element-to-calcium (X/Ca) ratios within biogenic calcium carbonate minerals are used as proxies to reconstruct past seawater temperature and composition. This study focuses on examining Li/Ca, B/Ca, and Mg/Ca ratios in sea urchins cultured at different temperatures and pCO₂ levels.

In situ secondary ion mass spectrometry (SIMS) analyses were conducted on two species of sea urchins cultured under controlled conditions and several species of paleo-echinoderms. A temperate species, Arbacia punctulata, was cultured at various pCO₂ levels (400, 600, 900, 2850 ppmv) with temperature held constant at 25°C. A tropical species, Echinometra viridis, was cultured in variable pCO₂ (400 and 1000 ppmv) and temperature (20°C and 30°C) conditions.

In the tropical species, a positive correlation was found between temperature and the analyzed (Li, B, Mg) element-to-calcium ratios of the spines, while variable responses to pCO₂ were observed. In the temperate species, a variable response to increasing pCO₂ was observed, with B/Ca having a similar trend to the calcification rate found in a previous study by Ries et al. (2009). Paleo-echinoderm samples varied in age from 518 to 53 Ma, and have a global distribution. The X/Ca ratios from paleo-echinoderms were used, along with the full range of observed partition coefficients (D^cX/Ca=X/Ca_carbonate/X/Ca_fluid, with X=Li, B, or Mg in this study) from the cultured sea urchins, to model element-to-calcium ratios of paleo-seawater.

The Last Glacial Maximum (LGM; ~23,000-19,000 years ago) and subsequent deglaciation (~19,000-11,000 years ago) represents the last major global climatological transition. In the Western United States, the LGM and deglacial were both characterized by increased effective moisture and expansive lake systems, with most lake growth and maximum lake extents achieved during the deglacial period. In stark contrast, the modern Great Basin is characterized by aridity and low effective moisture. The factors contributing to these large-scale changes in hydroclimates are critical to resolve, given this region is poised to undergo future anthropogenic-forced climate changes with large uncertainties in model simulations for the 21st century. Furthermore, there are ambiguous constraints on the magnitude and even the sign of changes in key hydroclimate variables between the LGM and present-day in both proxy reconstructions and climate model analyses of the Western United States.

In this work, I present new stable and clumped isotope data from several ancient lakes, analyze this new data in concert with previously published data, and compare both new and existing results to climate model simulations. Radiocarbon dated samples from ancient lakes constrain lake elevation and the timing of lake level fluctuations. Using a hydrological modeling framework, clumped isotope data constrain several other hydroclimate variables including temperature, precipitation rate, and evaporation rate, which are all used to assess climate model simulations of the same hydrological variables.

In Chapter 1, I compile new and existing radiocarbon ages from post-LGM lake basins, and provide an analysis of changing effective moisture through time and space. In Chapter 2, I provide a detailed analysis of our data from one specific basin, Lake Surprise, and provide evidence of evaporation depression as a key driver of lake growth. Finally, in Chapter 3, I use clumped and stable isotope analysis of samples collected across the Great Basin (by UCLA students and others) to provide evidence for spatial and temporal variation in hydroclimate. Concomitant analysis of proxy data and climate model simulations provides a robust means to understand past climate change, and by extension, predict how current hydroclimates may respond to expected future climate forcings.

Green chemistry encompasses a broad range of topics that enable us to understand and address major environmental issues. This dissertation advances multiple green chemistry topics through three independent projects: 1) Development of boron cluster-based cathode materials for use in developing a new approach to lithium-ion based energy storage. 2) Application of a quantitative probing technique for kinetic isotope effects, using the dual-clumped isotope proxy, to evaluate dissolved inorganic carbon transformation at geological sites being considered for use as CO2 storage sinks. 3) Advancing dual clumped isotopes as a next-generation probing technique to determine if terrestrial cave carbonate samples can be used to study climate through palaeothermometry and study kinetic isotope effects in speleothems.

Novel boron-cluster based molecules were synthesized for use as cathodes in lithium-ion batteries. The B12(OC7H6COOH)12 cluster exhibited the greatest potential for use as a cathode material in lithium-ion batteries. This novel molecule served as a scaffold for post-modification to enhance cyclability in the solid state. B12(OC7H6COOLi)12, a derivative of B12(OC7H6COOH)12, was deemed compatible with cell design and reversibly cycled for one redox event at an E1/2 of 3.4 V vs Li/Li+ in an in situ swagelock cell setup. However, this cluster suffered from specific capacity issues associated with only one (out of 2) reversible redox event and a high molecular weight relative to traditional metal oxides used in current generation cells.

CaCO3 samples recovered from The Cedars, peridotite-associated springs located in Northern California, were analyzed using the novel dual clumped isotope proxy to evaluate CO2 transformation processes and kinetic isotope effects and biases. Surface floe samples begin to precipitate out of solution within the first hour of CO2 absorption, and the DIC pool requires a residence time of approximately 100 hours to achieve isotopic equilibria. The D47/D48 slope of samples from the Cedars (-2.803�0.500; 1.s.e.) agrees with published values from lab experiments designed to constrain CO2 hydrolysis-related kinetic fractionation (-2.911�0.200). Ancient travertine samples that are close to equilibrium in the D47-D48 space yield an average temperature of 8.3�1.1 �C, suggesting that the conditions during that time were approximately 10�C colder than present day temperature. The consistency of slopes in the multi-isotope space suggests the D47-D48 dual carbonate clumped isotope framework can be applied to study CO2-absorption processes in applied systems including sites of interest for geological sequestration.

CaCO3 samples from terrestrial cave sites at 13 localities from around the world were analyzed using dual clumped isotope (D47-D48) system. Data showed that 27 samples exhibited isotopic equilibrium with the majority having D47-T predicted temperatures matching measured temperatures. 17 samples exhibited isotopic disequilibria in the D47-D48 space. Of the latter suite of samples, 15 fell within quadrant 3, 1 within quadrant 2, and 1 within quadrant 1 in the DD47-DD48 space. Samples that fell within quadrant 2 exhibited traditional degassing disequilibria consistent with previous speleothem studies. Samples which fell within quadrants 1 and 3 were identified to have oxygen and carbon isotope exchange within the Rayleigh distillation model approach, however the specific type of exchange could only be resolved in the DD47-DD48 space. Samples within quadrant 1 were identified to have oxygen isotope exchange while samples within quadrant 3 had carbon isotope exchange. Cave raft samples collected from Mexico exhibited the largest carbon isotope exchange phenomenon with magnitudes of disequilibria into quadrant 3 correlating to the relative ventilation from caves that they were recovered from. This study suggests the D47-D48 dual carbonate clumped isotope framework can be applied to varying types of cave carbonate samples enabling quick identification of (dis)equilibria for use in paleoclimate reconstruction applications.