1Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
2Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA
3School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
4School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
5Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
6Division of Geology and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
7Institut für Ionenphysik & Angewandte Physik, University of Innsbruck, Innsbruck, Austria
8Department of Earth and Planetary Sciences, University of California Berkeley, Berkeley, CA, USA
*now at: Chemical Sciences Division, Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
**now at: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
Received: 20 Dec 2010 – Discussion started: 21 Jan 2011
Abstract. Using measurements from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment, we show that methyl peroxy nitrate (CH3O2NO2) is present in concentrations of ~5–15 pptv in the springtime arctic upper troposphere. We investigate the regional and global effects of CH3O2NO2 by including its chemistry in the GEOS-Chem 3-D global chemical transport model. We find that at temperatures below 240 K inclusion of CH3O2NO2 chemistry results in decreases of up to ~20 % in NOx, ~20 % in N2O5, ~5 % in HNO3, ~2 % in ozone, and increases in methyl hydrogen peroxide of up to ~14 %. Larger changes are observed in biomass burning plumes lofted to high altitude. Additionally, by sequestering NOx at low temperatures, CH3O2NO2 decreases the cycling of HO2 to OH, resulting in a larger upper tropospheric HO2 to OH ratio. These results may impact some estimates of lightning NOx sources as well as help explain differences between models and measurements of upper tropospheric composition.
Revised: 27 Apr 2011 – Accepted: 28 Apr 2011 – Published: 06 May 2011
Browne, E. C., Perring, A. E., Wooldridge, P. J., Apel, E., Hall, S. R., Huey, L. G., Mao, J., Spencer, K. M., Clair, J. M. St., Weinheimer, A. J., Wisthaler, A., and Cohen, R. C.: Global and regional effects of the photochemistry of CH3O2NO2: evidence from ARCTAS, Atmos. Chem. Phys., 11, 4209-4219, doi:10.5194/acp-11-4209-2011, 2011.