Halogens in the coastal snow pack near Barrow, Alaska: Evidence for active bromine air-snow chemistry during springtime

• Published in: Geophysical Research Letters
• Main Authors: Simpson, William R., Alvarez-Aviles, Laura, Douglas, Thomas A., Sturm, Matthew, Domine, Florent
• Other Authors: Geophysical Institute Fairbanks, University of Alaska Fairbanks (UAF), Department of Chemistry and Biochemistry Fairbanks, ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Barrow; Alaska
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00374932; https://hal-insu.archives-ouvertes.fr/insu-00374932/document; https://hal-insu.archives-ouvertes.fr/insu-00374932/file/2004GL021748.pdf; https://doi.org/10.1029/2004GL021748

International audience We measured halide concentrations of snow and frost flowers in the vicinity of Barrow, Alaska. We find that the ratio of bromide to sodium in frost flowers is slightly enhanced (≈10%) as compared to sea water. In contrast, the ratio of bromide to sodium in some snow samples is more than an order of magnitude enhanced, and in other samples is more than an order of magnitude depleted. We interpret the bromide depleted snow as having been processed by heterogeneous chemistry and providing reactive halogen compounds to the atmosphere. The eventual end product of reactive bromine chemistry is HBr that is then deposited over a wide region, enhancing bromide in inland snow samples. Although frost flowers or open leads are likely to be the original source of halides that become reactive halogen gases, we find that the bromide release often occurs subsequent to production of aerosol from marine sources.