Maddie graduated in 2018 with a BSc in Geology & Geophysics and Environmental Engineering (double-major) from Yale University, where she studied climate and ocean science as well as geochemistry and paleoclimatology. She went on to pursue her interest in the ocean’s role in climate change by earning her MSc in Physical Oceanography (Distinction) from Bangor University in 2020, where her thesis involved coupling one-dimensional ocean circulation and ocean biogeochemistry models to elucidate the effect of sea ice retreat and the resulting wind-driven mixing on Arctic primary productivity.

Maddie is now conducting her PhD at St Andrews under a World-Leading St Andrews Doctoral Scholarship. Her research investigates the role of the Southern Ocean (the ocean around Antarctica) in atmospheric CO2 change over the last ice age. The Southern Ocean is one of the few places on Earth where the deep ocean – a major reservoir of carbon – comes in contact with the atmosphere. Because of this link, changes in Southern Ocean dynamics and biogeochemistry likely played a role in enabling carbon storage and release from the deep ocean on glacial-interglacial timescales.

Maddie’s research aims to quantify this carbon storage and release by producing high-resolution pH and CO2 records from the Southern Ocean. Maddie’s work uses the boron isotope-pH proxy in which she measures the boron isotopic composition of planktonic foraminifera in order to reconstruct past ocean-water pH (and by extension, CO2 content) back in time. She will analyze this data alongside multi-proxy records of biological pump efficiency, sea ice extent, and ocean circulation to evaluate potential mechanisms involved in Southern Ocean change. Maddie is also supplementing this data with ocean circulation and carbon cycle modelling experiments to better understand past Southern Ocean dynamics. By quantifying the carbon storage of the Southern Ocean and assessing driving mechanisms with proxy data and model output, Maddie hopes to elucidate the cause of glacial-interglacial CO2 change – a thus far elusive goal of paleoclimatologists.