My current research focuses on the role of the Southern Ocean during past intervals of climate change. I use geochemical tools to investigate two main topics: (1) the past variability of dust transport in the Southern Hemisphere and (2) past changes in Southern Ocean circulation.

1. The input of dust-borne Fe to the Southern Ocean is considered to have stimulated the primary production in the Southern Ocean and thus the drawdown of atmospheric CO₂ during past ice ages. Rare earth elements and the isotopic compositions of strontium, neodymium and lead provide a chemical fingerprint which I use to identify the terrestrial source regions of dust recovered from deep-sea sediments.

2. The Southern Ocean is a key region for the overturning and mixing of water masses within the global ocean circulation system. These processes influence the exchange of CO₂ between the ocean and the atmsophere. I use neodymium isotopes extracted from seawater-derived precipitates to learn about past changes in Southern Ocean circulation.