Seminar: Ulli Seibt

Tuesday, March 23, 2021 - 12:00pm

Ulli Seibt

Associate Professor, University of California, Los Angeles

Tropical photosynthesis through the lens of carbonyl sulfide

Photosynthetic carbon uptake is closely coupled to water availability. Photosynthesis is the main process driving the carbon cycle in land ecosystems, and one of the processes that introduce the largest uncertainties into climate change predictions. One of the fundamental issues is that photosynthetic carbon uptake cannot be measured directly at scales larger than a few leaves. In wet tropical environments, a second bottleneck arises because the absence of water vapor gradients makes it difficult to measure water fluxes. This limits our ability to predict how tropical photosynthesis will respond to climate change in this globally important biome. This presentation will describe how multi-scale field measurements and process-based modeling of Carbonyl Sulfide (COS) can provide insights into the coupling of carbon and water fluxes in a tropical rainforest, and discuss the potential impacts of increasing water stress on tropical carbon-water cycling under ongoing climate change.

Ulli Seibt is an associate professor in the Department of Atmospheric & Oceanic Sciences and Institute of the Environment and Sustainability at UCLA. She earned a diploma in Physics from University of Tübingen and PhD in Geosciences from the Max-Planck-Institute for Biogeochemistry in Jena, Germany. Ulli's research is on land ecosystem-atmosphere interactions, particularly carbon and water cycling in tropical, mediterranean and arctic systems as they are highly vulnerable to climate change impacts. Her work combines multi-tracer field observations with process-based modeling. Ulli has received a Marie Curie Postdoctoral Fellowship, and European Research Council Independent Investigator and NSF CAREER awards.

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