loading page

Satellite-Based Emission Estimates of Arctic Bromine and Application within GEOS-Chem
  • +7
  • Pamela A Wales,
  • Christoph A. Keller,
  • K. Emma Knowland,
  • Steven Pawson,
  • Sungyeon Choi,
  • Francois. Hendrick,
  • Michel Van Roozendael,
  • Ross J. Salawitch,
  • Raid Suleiman,
  • William Swanson
Pamela A Wales
Morgan State University

Corresponding Author:pamela.a.wales@nasa.gov

Author Profile
Christoph A. Keller
Universities Space Research Association
Author Profile
K. Emma Knowland
Morgan State University
Author Profile
Steven Pawson
NASA Goddard Space Flight Center
Author Profile
Sungyeon Choi
Science Systems and Applications, Inc.
Author Profile
Francois. Hendrick
Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
Author Profile
Michel Van Roozendael
Royal Belgian Institute for Space Aeronomy
Author Profile
Ross J. Salawitch
University of Maryland, College Park
Author Profile
Raid Suleiman
Harvard-Smithsonian Center for Astrophysics
Author Profile
William Swanson
University of Alaska Fairbanks
Author Profile


During polar spring, periods of elevated tropospheric bromine known as “bromine explosion events” are associated with near complete removal of surface ozone. The satellite-based Ozone Monitoring Instrument (OMI) provides total column measurements of bromine monoxide (BrO) with daily global coverage. In this study, we estimate springtime bromine emissions over the Arctic using OMI retrievals of BrO in combination with the GEOS-Chem (version 12.0.1) chemical mechanism, run online within the GEOS Earth System Model. Tropospheric hotspots of BrO are identified over the Arctic where the difference between OMI and modeled columns of BrO exceeds the bias observed over regions not impacted by bromine explosion emissions. The resulting hotspot columns are a lower-limit estimate for the portion of the OMI BrO signal attributable to bromine explosion events and are well correlated with BrO measured in the lower troposphere by buoy-based instruments. Daily flux of molecular bromine is calculated from hotspot columns of BrO based on the modeled atmospheric lifetime of inorganic bromine in the lower troposphere and partitioning of bromine species into BrO at OMI overpass time. Following the application of Arctic emissions in GEOS-Chem, OMI-based tropospheric hotspots of BrO are successfully modeled for 2008 – 2012 and periods of isolated, large (> 50%) decreases in surface ozone are captured during April and May. While this technique does not fully capture the low ozone observed at coastal stations, if a lower threshold is used to identify tropospheric hotspots of BrO, the representation of surface ozone in late spring is improved.