In order to predict and prepare for global change, we must improve our understanding of natural variability in the climate system over a variety of timescales. Globally, most instrumental weather measurements extend back less than 100 years. This window is far too short to understand how Earth’s climate can vary, especially in the light of the unprecedented changes brought on by anthropogenic climate change. Combine the short records with the low spatial density of observations in much of the world, and concerns about data quality, and it is clear that instrumental weather records cannot tell us the whole story. I am interested in using paleoclimate proxies, geologic and biological indicators of past climate, to expand our knowledge of how the climate system has varied in the past, and to better predict how climate will change in the future.

My Ph.D. research focuses on using a globally unique climate archive, sediment from Lake Bosumtwi, a 1.07 million-year-old crater impact lake in Ghana, to reconstruct past climate for western Africa. Lake Bosumtwi sediment is particularly valuable for paleoclimatic research because much of the record is annually laminated; the sediment contains climate information about individual years in the deep past. My work picks up where former DGESL student Tim Shanahan’s work left off, measuring elemental abundance in the annual layers using a scanning µ-XRF analyzer. Tim pioneered the use of the µ-XRF analyzer on Bosumtwi sediments, and showed that relative elemental abundance was correlated to precipitation at Lake Bosumtwi. My research will use these techniques and this sediment to answer several research questions of interest: How has climate varied at Lake Bosumtwi over the past 1 million years? How does the current interglacial compare to interglacials 120 and 400 thousand years ago when sea level was much higher? How is the tropical climate recorded at Lake Bosumtwi tied to climate in the North Atlantic? How long was the penultimate deglaciation?