Atmospheric & Environmental Chemistry Seminars

Clear Skies Ahead? New Challenges and Opportunities in Remote Sensing of Urban Air Quality

Jeff Geddes (Boston University)

Friday, Feb 9, 2024
12:00 pm to 1:00 pm | Pierce Hall, 100F | Remote option

Given the sparsity of traditional ground-based air quality monitoring, satellite observations are increasingly being used to study the unequally distributed impacts of air pollution. Exciting advances in satellite-based remote sensing of atmospheric chemistry, particularly from geostationary orbit, are expected to accelerate these efforts. It is imperative that we consider when, and to what extent, space-based retrievals are representative of the processes relevant to human exposures. Using a combination of in-situ and remote sensing observations complemented by high-resolution modeling, this presentation will highlight the interaction of air pollution and meteorology in complex urban systems and examine the implications for satellite-based measurements. We specifically leverage ground-based remote sensing measurements of nitrogen dioxide in Boston and Salt Lake City to study the link between total column abundance (as would be retrieved from satellites) and surface concentrations relevant to ambient exposures. Our work confirms that satellite observations are uniquely challenged under certain conditions and in specific settings. We show that gradients in pollution inferred by the total column abundance are not always representative of, and may even be in opposite directions to, gradients in pollution observed at the ground. Opportunities to address these challenges and advance the understanding of urban air quality with remote sensing will be discussed.

Speaker Bio

Jeff is an Assistant Professor in the Department of Earth & Environment at Boston University. Before joining BU, he earned a PhD in Chemistry from the University of Toronto and was a postdoctoral fellow at Dalhousie University and at MIT. Research in the Geddes group is focused on advancing the use of satellite observations to study urban air pollution and understanding interactions between meteorology and air quality in complex urban environments. Jeff contributed algorithm developments for retrievals of nitrogen dioxide from the recently launched TEMPO satellite instrument, and his group has led ground-based remote sensing deployments with Pandoras in Boston and Salt Lake City. Jeff is also interested in improving our understanding of feedbacks between the biosphere and atmospheric chemistry under global change using chemical transport models. Jeff is a member of the GEOS-Chem steering committee, co-chairing the Surface-Atmosphere Exchange model working group. He is also a member of the WMO Steering Committee for Measurement Model Fusion of Global Atmospheric Deposition, and of the WMO Expert Team on Atmospheric Composition Network Design and Evolution.


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