We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Atmospheric nitrogen oxides (NO and NO<sub>2</sub>) at Dome C, East Antarctica, during the OPALE campaign.
- Authors
Frey, M. M.; Roscoe, H. K.; Kukui, A.; Savarino, J.; France, J. L.; King, M. D.; Legrand, M.; Preunkert, S.
- Abstract
Mixing ratios of the atmospheric nitrogen oxides NO and NO2 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, 3233m), during December 2011 to January 2012. Profiles of NOx mixing ratios of the lower 100m of the atmosphere confirm that, in contrast to South Pole, air chemistry at Dome C is dominated by strong diurnal cycles in solar irradiance and atmospheric stability. Depth profiles of mixing ratios in firn air suggest that the upper snowpack at Dome C holds a significant reservoir of photolytically produced NO and is a sink of gas phase ozone (O3). First-time observations of BrO at Dome C suggest 2-3 pptv near the ground, with higher levels in the free troposphere. Assuming steady-state, observed mixing ratios of BrO and RO2 radicals are too low to explain the large NO2: NO ratios found in ambient air. A previously not considered interference with pernitric acid (HNO4) may explain part of this inconsistency. During 2011-2012 NOx mixing ratios and flux were larger than in 2009-2010 consistent with also larger surface O3 mixing ratios resulting from increased net O3 production. Large NOx mixing ratios arose from a combination of changes in mixing height and NOx snow emission flux F... . During 23 December 2011-12 January 2012 median F... 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... in December 2011 was largely due to changes in snow pack 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 O3 and associated increase in NO-3 photolysis rates. Systematic changes in the quantum yield of NO-3 photolysis over time may contribute to the observed F... variability.
- Subjects
EAST Antarctica (Antarctica); SOUTH Pole; ATMOSPHERIC nitrogen oxides; MIXING ratio (Atmospheric chemistry); TROPOSPHERE; ATMOSPHERIC ozone; SINKS (Atmospheric chemistry)
- Publication
Atmospheric Chemistry & Physics Discussions, 2014, Vol 14, Issue 22, p31281
- ISSN
1680-7367
- Publication type
Article
- DOI
10.5194/acpd-14-31281-2014