My research focuses on the variability and long-term controls on regional rainfall. I use chemical and biological traces left by past climates, called proxies, to understand how regional hydroclimate changed in the past. I use these measurements to ‘benchmark’ climate model simulations and identify the specific physical mechanisms behind particular past climate changes.
My dissertation focused on improving understanding of droughts in the last 2000 years in Mesoamerica. I studied lakes in the mountains of Central Mexico that contain high-resolution sedimentary archives, and used ancient pollen, sediment chemistry and the isotopic composition of authigenic calcite to reconstruct past droughts. This work was instrumental in identifying relationships between climate and pre-Columbian societal changes as well as shedding light on the linkages between local Mesoamerican drought and the larger climate system.
As a postdoctoral researcher at the University of Arizona, I am expanding my ‘toolkit’ for studying past climates by utilizing organic geochemical techniques to reconstruct the history of the North American Monsoon (NAM) since the last Ice Age (last Glacial Maximum, ~21 ka BP). The NAM is critical to regional hydrology in the Southwest, but is one of the least understood monsoon systems. Our measurements of the isotopic composition of ancient leaf waxes are providing exciting insights into its long-term variability. We are also exploring the fundamental mechanisms that produce the NAM and other monsoon circulations using idealized climate model simulations.