Roberta Hamme is a Canadian chemical oceanographer from the University of Victoria, visiting LOV for a one-year sabbatical. Her research group makes and uses observations of dissolved gases to answer questions about the marine carbon cycle. They have been using oxygen measurements from Argo floats to investigate air-sea interactions and deoxygenation. Her lab makes high precision discrete measurements of noble gases to understand how physical processes affect gases, of oxygen/argon ratios to quantify biological productivity, and of nitrogen/argon ratios to determine nutrient loss by denitrification and related processes. Her group also collaborates with modellers to investigate these same processes in numerical simulations.