Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Legrand, Michel, Preunkert, S, Frey, M, Bartels-Rausch, Th, Kukui, Alexandre, King, M.D., Savarino, J, Kerbrat, M, Jourdain, B
• Other Authors: Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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 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)-Centre National de la Recherche Scientifique (CNRS), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Laboratory of Radio- and Environmental Chemistry Villigen, Paul Scherrer Institute (PSI), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales Paris (CNES), School of Earth Sciences Bristol, University of Bristol Bristol, NERC NE/F0004796/1 and NE/F010788, and NERC FSF grants 555.0608 and 584.0609, Institut Polaire Français-Paul Emile Victor (IPEV), Italian colleagues from Meteo- Climatological Observatory of PNRA for the meteorological data collected at Concordia., ANR-09-BLAN-0226,OPALE(2009), ANR-11-JS56-0005,MONISNOW,Suivi temporel de la neige dans un climat changeant(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: [SDU]Sciences of the Universe [physics]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarc*; Antarctic
• Online Access: https://insu.hal.science/insu-01130764; https://insu.hal.science/insu-01130764/document; https://insu.hal.science/insu-01130764/file/acp-14-9963-2014.pdf; https://doi.org/10.5194/acp-14-9963-2014

International audience During the austral summer 2011/2012 atmospheric nitrous acid (HONO) was investigated for the second time at the Concordia site (75 • 06 S, 123 • 33 E), located on the East Antarctic Plateau, by deploying a long-path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35 ± 5.0 pptv) were similar to those measured in December 2010/January 2011 (30.4 ± 3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation of NO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gas-phase HONO at mixing ratios half that of the NO x mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NO x from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8 × 10 9 molecules cm −2 s −1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation , these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO 4 had biased the measurements of HONO.