Atmospheric nitrogen oxides (NO and NO 2 ) at Dome C, East Antarctica, during the OPALE campaign

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Frey, N. M., Roscoe, H. K., Kukui, Alexandre, Savarino, Joël A., France, J. L., King, M.D., Legrand, Michel, Preunkert, Susanne
• Other Authors: British Antarctic Survey (BAS), Natural Environment Research Council (NERC), 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), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), School of Environmental Sciences Norwich, University of East Anglia Norwich (UEA), School of Earth Sciences Bristol, University of Bristol Bristol, Université Joseph Fourier - Grenoble 1 (UJF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDE]Environmental Sciences; Antarctic; East Antarctica; South Pole; The Antarctic; Antarc*; Antarctica; South pole
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01178180; https://hal-insu.archives-ouvertes.fr/insu-01178180/document; https://hal-insu.archives-ouvertes.fr/insu-01178180/file/acp-15-7859-2015.pdf; https://doi.org/10.5194/acp-15-7859-2015

International audience Mixing ratios of the atmospheric nitrogen oxides NO and NO 2 were measured as part of the OPALE (Oxidant Production in Antarctic Lands & Export) campaign at Dome C, East Antarctica (75.1°S, 123.3°E, 3233 m), during December 2011 to January 2012. Profiles of NO x mixing ratios of the lower 100 m of the atmosphere confirm that, in contrast to the South Pole, air chemistry at Dome C is strongly influenced by large diurnal cycles in solar irradiance and a sudden collapse of the atmospheric boundary layer in the early evening. Depth profiles of mixing ratios in firn air suggest that the upper snowpack at Dome C holds a significant reservoir of photolytically produced NO 2 and is a sink of gas-phase ozone (O 3 ). First-time observations of bromine oxide (BrO) at Dome C show that mixing ratios of BrO near the ground are low, certainly less than 5 pptv, with higher levels in the free troposphere. Assuming steady state, observed mixing ratios of BrO and RO 2 radicals are too low to explain the large NO 2 : NO ratios found in ambient air, possibly indicating the existence of an unknown process contributing to the atmospheric chemistry of reactive nitrogen above the Antarctic Plateau. During 2011–2012, NO x mixing ratios and flux were larger than in 2009–2010, consistent with also larger surface O 3 mixing ratios resulting from increased net O 3 production. Large NO x mixing ratios at Dome C arise from a combination of continuous sunlight, shallow mixing height and significant NO x emissions by surface snow (F NO x ). During 23 December 2011–12 January 2012, median F NO x was twice that during the same period in 2009– 2010 due to significantly larger atmospheric turbulence and a slightly stronger snowpack source. A tripling of F NO x in December 2011 was largely due to changes in snowpack source strength caused primarily by changes in NO 3 - concentrations in the snow skin layer, and only to a secondary order by decrease of total column O 3 and associated increase in NO 3 - photolysis rates. A ...