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East Asian summer monsoon (EASM) rainfall impacts the world's most populous regions. Accurate EASM rainfall prediction necessitates robust paleoclimate reconstructions from proxy data and quantitative linkage to modern climatic conditions. Many precisely dated oxygen isotope records from Chinese stalagmites have been interpreted as directly reflecting past EASM rainfall amount variability, but recent research suggests that such records instead integrate multiple hydroclimatic processes. Using a Lagrangian precipitation moisture source diagnostic, we demonstrate that EASM rainfall is primarily derived from the Indian Ocean. Conversely, Pacific Ocean moisture export peaks during winter, and the moisture uptake area does not differ significantly between summer and winter and is thus a minor contributor to monsoonal precipitation. Our results are substantiated by an accurate reproduction of summer and winter spatial rainfall distributions across China. We also correlate modern EASM rainfall oxygen isotope ratios with instrumental rainfall amount and our moisture source data. This analysis reveals that the strength of the source effect is geographically variable, and differences in atmospheric moisture transport may significantly impact the isotopic signature of EASM rainfall at the Hulu, Dongge, and Wanxiang Cave sites. These results improve our ability to isolate the rainfall amount signal in paleomonsoon reconstructions and indicate that precipitation across central and eastern China will directly respond to variability in Indian Ocean moisture supply.

Carbon dioxide concentration variability in caves has implications for palaeoclimatic research involving stalagmites, the conservation of cave art, condensation corrosion, and safety during cave exploration. Here we present a high-resolution spatial survey of cave air carbon dioxide partial pressure (PCO2) in the 1.5km Scoska Cave system in North Yorkshire, UK, constructed using measurements taken during the interval of July 1 – July 5, 2008. According to the spatial PCO2 survey, 76% of the cave air PCO2 increase occurred within the first ~50 metres; consequently the PCO2 gradient throughout the rest of the cave was slight. As is the case in other caves, this suggests that a ‘front’ exists at this site between high PCO2 cave air and low PCO2 outside air, where the PCO2 increases dramatically over a short distance. Temperature data support this interpretation. This CO2 ‘front’ is thought to represent the farthest point reached by large-scale advection of air out of the cave, and its position is hypothesized to fluctuate depending on atmospheric conditions. Thus, distinct PCO2 trends characterize sections of the Scoska Cave system, which result in spatial variability in calcite deposition and redissolution. Modelled stalagmite growth rates vary between negligible and 0.21 mm yr-1, depending on unconstrained drip water [Ca2+] values and cave atmosphere PCO2. Assuming constant drip water [Ca2+], optimum calcite deposition occurs near to the cave entrance, where ventilation and advection reduce PCO2 levels most effectively. However, calcite precipitation on the roof of the cave may partially control the [Ca2+] of drip water that reaches the floor, so although the link between overall calcite deposition (i.e., on the roof and the floor) and PCO2 appears robust, the effect of variable cave air PCO2 on stalagmite growth rates requires more research. These calculations suggest that calcite precipitation rates in different areas of Scoska Cave may differ due to local PCO2 and temperature variability, highlighting the benefits of thoroughly understanding site-specific cave environmental factors prior to the interpretation of stalagmite-based palaeoclimate records.

This thesis serves as a written accompaniment for an interactive installation art project. In addition to a detailed description and evaluation of the other components of the project, it also features a number of abstract discussions on pertinent topics, and describes how the outcomes of these lines of research informed the final iteration of the installation.\ud \ud \ud The project is a sonic art installation that explores several concepts, uniting them to create an audience experience that is intended to be both novel and accessible. It deals with the experience of physical space and structure, and how it can be complemented sonically, emphasising and reimagining the structure with sound. The structure and generated sound are intrinsically linked, and this relationship is exploited to transform the perception of space for artistic effect. The installation also places heavy emphasis on collective interaction. All audience members experience the same sound (albeit from a different position and perspective), so their interactions all affect each other. The installation was designed to optimise this paradigm of interaction, and it is a point of interest to observe what happens in this regard. Complementary to the exploration of physical structure and space is experimentation with physical materials and how they can be expressed sonically. Since all of the sound in the piece has its foundation in sounds recorded by contact microphones attached to the materials that make up the structure, a relationship of some form is inherent, and further expression can be established by manipulating and transforming the sound.