Polar nighttime chemistry produces intense reactive bromine events

• Published in: Geophysical Research Letters
• Main Authors: Simpson, W., R., Friess, U., Thomas, Jennie L., Lampel, J., Platt, U.
• Other Authors: Geophysical Institute Fairbanks, University of Alaska Fairbanks (UAF), Department of Chemistry and Biochemistry Fairbanks, Institut für Umweltphysik Heidelberg, Universität Heidelberg Heidelberg = Heidelberg University, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Barrow; polar night; Alaska
• Online Access: https://insu.hal.science/insu-01877525; https://insu.hal.science/insu-01877525/document; https://insu.hal.science/insu-01877525/file/2018GL079444.pdf; https://doi.org/10.1029/2018GL079444

International audience By examining the origin of air masses that arrive at Utqiaġvik (formerly Barrow) Alaska soon after polar sunrise (late January/early February), we identified periods when air arriving at Utqiaġvik had previously resided primarily at higher latitudes in near total darkness. Upon illumination, these air masses produced high concentrations of reactive bromine, which was detected by differential optical absorption spectroscopy (DOAS) as bromine monoxide (BrO). These observations are consistent with nighttime production of a photolabile reactive bromine precursor (e.g. Br2 or BrCl). A large polar‐night source of photolabile reactive bromine precursors would contribute seed reactive bromine to daytime reactive bromine events and could export reactive halogens to lower latitudes and the free troposphere.