EGU24-11717, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Discovering global-scale processes in the marine atmosphere

Lucy Carpenter1, Anna Callaghan1, Rosie Chance1, Mat Evans1, James Lee1, Katie Read1, Matthew Rowlinson1, Marvin Shaw1, Tomas Sherwen1, Simone Andersen2, Liselotte Tinel3, and John Plane4
Lucy Carpenter et al.
  • 1Department of Chemistry, University of York, York, UK (
  • 2Max Planck Institute for Chemistry, Mainz, Germany (
  • 3IMT Nord Europe, Lille Douai, France (
  • 4School of Chemistry, University of Leeds, Leeds, UK (

Measurements in the remote unpolluted atmosphere have tremendous power to reveal processes that are happening on a global scale.   In the marine atmosphere where nitrogen oxide (NOx) levels are very low,  the photochemical loss rate of tropospheric ozone dominates over production, allowing loss processes to be sensitively explored.   We showed that bromine and iodine emitted from open-ocean marine sources initiate important global-scale catalytic ozone-destroying cycles and found that the deposition of ozone and subsequent reactions at the sea surface are a substantial pathway for production of volatile iodine.   Production of ozone in the remote atmosphere is predominantly regulated by the abundance of NOx, which also exerts substantial control over the hydroxyl radical (OH), the most important oxidant in the atmosphere.  It is now emerging that NOx regeneration pathways, namely the photolysis of particulate nitrate, could provide the dominant source of NOx to the marine atmosphere.  This has significant implications for our understanding of the chemistry of the remote troposphere.  This presentation discusses advances made in understanding these important, predominantly natural, cycles and their impacts on the atmosphere.

How to cite: Carpenter, L., Callaghan, A., Chance, R., Evans, M., Lee, J., Read, K., Rowlinson, M., Shaw, M., Sherwen, T., Andersen, S., Tinel, L., and Plane, J.: Discovering global-scale processes in the marine atmosphere, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11717,, 2024.