Articles | Volume 24, issue 6
Research article
 | Highlight paper
20 Mar 2024
Research article | Highlight paper |  | 20 Mar 2024

Observations of cyanogen bromide (BrCN) in the global troposphere and their relation to polar surface O3 destruction

James M. Roberts, Siyuan Wang, Patrick R. Veres, J. Andrew Neuman, Michael A. Robinson, Ilann Bourgeois, Jeff Peischl, Thomas B. Ryerson, Chelsea R. Thompson, Hannah M. Allen, John D. Crounse, Paul O. Wennberg, Samuel R. Hall, Kirk Ullmann, Simone Meinardi, Isobel J. Simpson, and Donald Blake

Data sets

ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols, Version 2 S. C. Wofsy et al.

Executive editor
Bromine chemistry in polar regions is important for the composition of the atmosphere as well as climate. Reactive bromine strongly affects the oxidation capacity and the local ozone budget, and through the export to lower latitudes, it affects the ozone budget and the atmosphere's radiative properties outside polar regions. The newly identified bromine reservoir changes our understanding of the chemical budgets of polar halogens which will have implications for the ozone and mercury removal cycles.
Short summary
We measured cyanogen bromide (BrCN) in the troposphere for the first time. BrCN is a product of the same active bromine chemistry that destroys ozone and removes mercury in polar surface environments and is a previously unrecognized sink for active Br compounds. BrCN has an apparent lifetime against heterogeneous loss in the range 1–10 d, so it serves as a cumulative marker of Br-radical chemistry. Accounting for BrCN chemistry is an important part of understanding polar Br cycling.
Final-revised paper