the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Bromine and Iodine in Atmospheric Mercury Oxidation
Abstract. We investigate atmospheric oxidation of mercury Hg(0) by halogens, initiated by Br and I to yield Hg(I), and continued by I, Br, BrO, ClO, IO, NO2 and HO2 to yield Hg(II) or Hg(0), using computational methods with focus on creation of data for determining the impact of rising iodine levels. We calculate reaction enthalpies and Gibbs free energies using the Coupled Cluster singlets, doublets, and perturbative triplets method (CCSD(T)) with the ma-def2-TZVP basis set and effective core potential to account for relativistic effects. Additionally, we investigate reaction kinetics using variational transition state theory based on geometric scans of bond dissociations at the CASPT2/ma-def2-TZVP level. We compare the results obtained from both methods to help define the uncertainty. Our results provide insights into the mechanisms of these reactions, and the data produced get us closer to determining iodine’s impact on mercury depletion events and on the atmosphere as a whole. The reaction ·HgBr+Br·->HgBr2 was found to be twice as fast as HgI·+I·->HgI2 with reaction rate coefficients of 8.8x10−13 and 4.2x10−13 cm3 molecule−1 s−1 respectively. The BrHg·+BrO·->BrHgOBr reaction was about 7.2 times faster than the ·HgI+IO·->IHgOI reaction with their rates being 3.3x10−14 and 4.6x10−15 cm3 molecule−1 s−1 respectively. We investigate the Hg•XOY (X and Y being halogen) complexes. From the reactions investigated including iodine, the reaction with the most plausible chance of impacting the mercury lifetime in the atmosphere is HgI·+I·->HgI2.
Status: open (until 14 Mar 2025)
-
CC1: 'Comment on egusphere-2025-116', Henrik Skov, 31 Jan 2025
reply
There is a wrong citation:
ref. 27. Goodsite, M. E., Skov, H., Christensen, J. H., Heidam, N. Z., Jensen, B., and W˚ahlin, P.: Fate of elemental mercury in the Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the Arctic. Antarctic springtime depletion of atmospheric mercury, Environmental Science & Technology, 38, 2373–2382, 2004.
Should be:
Skov, H. Christensen, J. Goodsite, M.E. Heidam, N.Z. Jensen, B. Wåhlin, P. and Geernaert, G. (2004) “The fate of elemental mercury in Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to Arctic” ES & T. vol. 38, 2373-2382.
Citation: https://doi.org/10.5194/egusphere-2025-116-CC1 -
CC2: 'Reply on CC1', Svend L. Bager, 01 Feb 2025
reply
Thanks for letting us know. We will make sure the correction is included.
Citation: https://doi.org/10.5194/egusphere-2025-116-CC2
-
CC2: 'Reply on CC1', Svend L. Bager, 01 Feb 2025
reply
Viewed
Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.
HTML | XML | Total | BibTeX | EndNote | |
---|---|---|---|---|---|
55 | 0 | 0 | 55 | 0 | 0 |
- HTML: 55
- PDF: 0
- XML: 0
- Total: 55
- BibTeX: 0
- EndNote: 0
Viewed (geographical distribution)
Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.
Country | # | Views | % |
---|
Total: | 0 |
HTML: | 0 |
PDF: | 0 |
XML: | 0 |
- 1