Columbia Climate School's Office of Faculty Affairs is pleased to announce Ursula Jongebloed will deliver our April research seminar, “The role of phytoplankton and volcanoes in sulfate aerosols over the industrial era,” on Wednesday, April 15, from 11:00 AM - 12:30 PM in the Hogan Hall A-level Conference Room, at 2910 Broadway.
If joining on Zoom, RSVP here. You will receive the Zoom link the day before the event. If you cannot access this link, please email [email protected] to be added to the Zoom list. Light refreshments will be served.
Abstract: Aerosols are small particles in the atmosphere that have a cooling effect on global climate. Sulfate aerosols have the largest cooling effect of any aerosol and also represent the largest source of uncertainty in future climate projections. Here we measure sulfur isotopes of sulfate in Greenland ice cores to determine how sulfate aerosol sources and oxidation chemistry have changed from over the industrial era. We report two major findings. First, passive volcanic degassing is an underestimated source of atmospheric sulfur due to the underestimated contribution of hydrogen sulfide emissions from quiescent volcanoes. Second, we find that the industrial-era decline in ice core methanesulfonic acid, which was previously interpreted as a sign of collapsing phytoplankton populations, was actually driven by pollution. These findings have changed our understanding of sulfate aerosol sources and chemistry, with implications for estimating the influence of sulfate aerosols on global climate.
Bio: Ursula Jongebloed is a postdoctoral fellow at MIT interested in atmospheric chemistry and climate science. Ursula’s PhD work at the University of Washington used stable isotopes in environmental samples and global models of atmospheric composition to study sulfate aerosol sources and chemistry. At MIT, Ursula is studying isoprene oxidation as a source of atmospheric pollutants such as formaldehyde. Prior to her PhD, Ursula received her B.A. in Chemistry and Earth Sciences at Dartmouth College.
