Susan Lozier is Ronie-Richelle Garcia-Johnson Professor of Ocean Sciences at Duke University. Dr. Lozier is a physical oceanographer who studies large-scale ocean circulation, and her research focuses on the ocean’s role in climate variability and climate change. She studies the large-scale meridional overturning circulation of the ocean and how that circulation impacts the transfer of heat and fresh water from one part of the ocean to another, and is currently the international project lead for OSNAP (o-snap.org), an observing system designed to measure the meridional overturning in the subpolar North Atlantic.
Video now available of the 16th Annual Revelle Lecture
In 1800 Count Rumford ascertained the ocean’s meridional overturning circulation from a single profile of ocean temperature constructed with the use of a rope, a wooden bucket, and a rudimentary thermometer. Over two centuries later, arrays of gliders, floats, and moorings are deployed across the span of the North Atlantic to measure the overturning circulation and its spatial and temporal variability. While Rumford appreciated the role of the ocean’s overturning in redistributing heat, today we understand the crucial role that this circulation plays in sequestering anthropogenic carbon dioxide in the deep ocean. What we don’t understand, however, are the mechanisms that control the overturning strength and how and why the overturning will change in the decades ahead. This information is crucial to our understanding of the climate system, because the extent to which the ocean will continue to be a heat and carbon reservoir depends on the strength of the overturning. While we have reasons to reject the popularized ocean conveyor belt as a paradigm for the overturning, oceanographers are just now piecing together the complex flow patterns that bring warm waters poleward and cold water equatorward. As the pieces are coming together, some long-held assumptions have been overturned, and some new paradigms are surfacing.
