The multi-seasonal NO_y budget in coastal Antarctica and its link with surface snow and ice core nitrate: results from the CHABLIS campaign

A. E. Jones (1) , E. W. Wolff (1) , D. Ames (2) , S. J.-B. Bauguitte (1) , K. C. Clemitshaw (2) , Z. Fleming (2) , G. P. Mills (3) , A. Saiz-Lopez (3) , R. A. Salmon (1) , W. T. Sturges (3) , D. R. Worton (3)

1 BAS - British Antarctic Survey
2 Dept. of Environmental Science and Technology
3 School of Environmental Sciences [Norwich]

Measurements of individual NO_y components were carried out at Halley station in coastal Antarctica. The measurements were made as part of the CHABLIS campaign (Chemistry of the Antarctic Boundary Layer and the Interface with Snow) and cover over half a year, from austral winter 2004 through to austral summer 2005. They are the longest duration and most extensive NO_y budget study carried out to date in polar regions. Results show clear dominance of organic NO_y compounds (PAN and MeONO₂) during the winter months, with low concentrations of inorganic NO_y, but a reversal of this situation towards summer when the balance shifts in favour of inorganic NO_y. Multi-seasonal measurements of surface snow nitrate correlate strongly with inorganic NO_y species. One case study in August suggested that particulate nitrate was the dominant source of nitrate to the snowpack, but this was not the consistent picture throughout the measurement period. An analysis of NO_x production rates showed that emissions of NO_x from the snowpack dominate over gas-phase sources of "new NO_x", suggesting that, for certain periods in the past, the flux of NO_x into the boundary layer can be calculated from ice core nitrate data.

Domaines: Océan, Atmosphère

A. E. Jones, E. W. Wolff, D. Ames, S. J.-B. Bauguitte, K. C. Clemitshaw, et al.. The multi-seasonal NO_y budget in coastal Antarctica and its link with surface snow and ice core nitrate: results from the CHABLIS campaign. Atmospheric Chemistry and Physics Discussions, 2007, 7 (2), pp.4127-4163. ⟨hal-00302680⟩