The Role of Reactive Halogens in Air Pollution and Climate

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Prof. Becky Alexander

Director of the Program on Climate Change

University of Washington

Monday September 28, 2020, 2 PM



Reactive halogens are best known for their influence on stratospheric ozone depletion.  Halogens also impact tropospheric chemistry, with implications for air pollution and climate. Although we’ve known since the 1980s that reactive halogens are responsible for springtime Arctic ozone depletion events, their global impacts are still unknown. Due to complex chemistry and challenges in measuring reactive halogens, atmospheric chemists are only just beginning to understand its importance and the magnitude of their impacts. In this talk I present evidence from ice core measurements and global modeling that tropospheric reactive halogen abundances have changed significantly in the past due to both natural climate change and anthropogenic emissions. I will discuss the potential implications for climate and air pollution, both in the past and into the future.



Becky Alexander is a Professor in the Department of Atmospheric Sciences and the Director of the Program on Climate Change at the University of Washington (UW). She earned her Ph.D. in chemistry at the University of California, San Diego, and was awarded a NOAA Climate and Global Change Postdoctoral Fellowship to work in the Department of Earth and Planetary Sciences at Harvard University. Her research group studies air pollution and feedbacks between atmospheric chemistry and climate using ice-core and aerosol observations and global chemistry-climate models.


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Sep 28 2020


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