An Inverse Approach to Understanding Deglacial Benthic Oxygen Isotope Records from the Last Glaciation

Daniel Amrhein, S.M., 2014
Carl Wunsch, Advisor

Observations suggest that during the last deglaciation (roughly 20,000-10,000 years ago) the Earth warmed substantially, global sea level rose approximately 100 meters, and atmospheric concentrations of carbon dioxide increased. The ocean plays a key role in the modern climate system by storing and transporting heat, salt, and nutrients, but its role during the last deglaciation remains uncertain.

This thesis develops and applies an inverse framework for understanding last-deglacial oxygen isotope records derived from sediment cores using a Green function approach. Eight sediment core records and a model of the modern ocean tracer transport constrain a solution for global mixed layer tracer concentration histories. The solution, found using singular value decomposition, reflects the resolving power of the data, which is highest at model surface locations associated with large rates of volume flux into the deep ocean.