Iodine speciation in snow during the MOSAiC expedition and its implications for Arctic iodine emissions
Photochemical release of iodine from snow has been suggested as a source of reactive iodine to the Arctic atmosphere, however understanding of the underlying mechanism and potential source strength is hindered by a lack of measurements of iodine concentration and speciation in snow. Moreover, the origin of snow iodine is also unknown. Here, we report iodine speciation measurements in Arctic snow on sea ice at a range of snow depths from 177 samples, representing 80 sampling events, from December 2019 to October 2020 collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. We demonstrate that while there appears to be a source of iodine, in particular iodate, to the base of the snow over first year ice, this does not influence iodine concentration in the surface snow. There is instead evidence of a top-down source of iodine, potentially from iodine-enriched marine aerosol, as well as some evidence for episodic influx of iodate with dust. The potential for photochemical release of molecular iodine (I<sub>2</sub>) from iodide in surface snow was investigated, and it was demonstrated that this could provide an iodine emission flux to the Arctic atmosphere comparable to oceanic fluxes. Knowledge of the prevalence and speciation of iodine in Arctic snow will contribute to better understanding of its contribution to observed concentrations of polar iodine oxide (IO), and hence its contribution to the depletion of tropospheric ozone in the Arctic.
Authors
- M. M. Frey (ORCID: https://orcid.org/0000-0003-0535-0416)
- Lucy V. Brown (ORCID: https://orcid.org/0000-0001-7494-5443)
- Matthew Rowlinson (ORCID: https://orcid.org/0000-0002-5236-6536)
- Amy R. Macfarlane (ORCID: https://orcid.org/0000-0002-1638-8885)
- Ryan J. Pound (ORCID: https://orcid.org/0000-0003-1547-6565)
- Stefanie Arndt (ORCID: https://orcid.org/0000-0001-9782-3844)
- Hans‐Werner Jacobi (ORCID: https://orcid.org/0000-0003-2230-3136)
- Martin Schneebeli (ORCID: https://orcid.org/0000-0003-2872-4409)
- Samantha Miller (ORCID: https://orcid.org/0009-0002-2659-6044)
- L. Ganzeveld
- Stephen D. Archer (ORCID: https://orcid.org/0000-0001-6054-2424)
- Daniela Krampe (ORCID: https://orcid.org/0000-0003-0633-5023)
- Detlev Helmig (ORCID: https://orcid.org/0000-0003-1612-1651)
- Matthias Jaggi (ORCID: https://orcid.org/0000-0003-0940-2375)
- Ruzica Dadić (ORCID: https://orcid.org/0000-0003-1303-1896)
- Lucy J. Carpenter (ORCID: https://orcid.org/0000-0002-6257-3950)
- Rosie Chance (ORCID: https://orcid.org/0000-0002-5906-176X)
- Johannes G. M. Barten (ORCID: https://orcid.org/0000-0001-6534-1410)
- Henna-Reetta Hannula (ORCID: https://orcid.org/0000-0003-0792-8795)
- Byron Blomquist (ORCID: https://orcid.org/0000-0002-3366-6269)
- Matthew R. Jones (ORCID: https://orcid.org/0000-0001-8077-2331)
Institutions
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (DE)
- Finnish Meteorological Institute (FI)
- Centre National de la Recherche Scientifique (FR)
- National Oceanic and Atmospheric Administration (US)
- British Antarctic Survey (GB)
- Natural Environment Research Council (GB)
- Universität Hamburg (DE)
- Cooperative Institute for Research in Environmental Sciences (US)
- University of Colorado Boulder (US)
- Bigelow Laboratory for Ocean Sciences (US)
- Northumbria University (GB)
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (FR)
- Institut des Géosciences de l'Environnement (FR)
- NOAA Physical Sciences Laboratory (US)
- Ruhrverband (Germany) (DE)
- Institut de Recherche pour le Développement (FR)
- University of York (GB)
- UiT The Arctic University of Norway (NO)
- Université Grenoble Alpes (FR)
- Wageningen University & Research (NL)
Publication Details
- Journal
- Faraday Discussions
- Published
- 2024-12-06
- DOI
- https://doi.org/10.1039/d4fd00178h
- Citations
- 3
- Primary Topic
- Atmospheric chemistry and aerosols
- Type
- article
- Field-Weighted Citation Impact
- 1.13
Funders
- National Science Foundation
- WSL-Institut für Schnee- und Lawinenforschung SLF
- Sight Research UK
- European Commission
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Universität Hamburg
- Swiss Polar Institute
- Swiss Federal Institute for Forest, Snow and Landscape Research
- Horizon 2020 Framework Programme
- Natural Environment Research Council
- Office of Polar Programs
- British Antarctic Survey