Global and regional effects of the photochemistry of CH 3 O 2 NO 2 : evidence from ARCTAS

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 (CH 3 O 2 NO 2 ) is present in concentrations of ~5–15 pptv in the springtime arctic upper troposphere. We investigate the regio...

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Bibliographic Details
Published in:Atmospheric Chemistry and Physics
Main Authors: J. M. St. Clair, A. J. Weinheimer, A. Wisthaler, K. M. Spencer, J. Mao, L. G. Huey, S. R. Hall, E. Apel, P. J. Wooldridge, E. C. Browne, A. E. Perring, R. C. Cohen
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2011
Subjects:
Physics
QC1-999
Chemistry
QD1-999
Arctic
Online Access:https://doi.org/10.5194/acp-11-4209-2011
https://doaj.org/article/b0fc51c8e1774458b9048fc4d4ed8115
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Summary: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 (CH 3 O 2 NO 2 ) is present in concentrations of ~5–15 pptv in the springtime arctic upper troposphere. We investigate the regional and global effects of CH 3 O 2 NO 2 by including its chemistry in the GEOS-Chem 3-D global chemical transport model. We find that at temperatures below 240 K inclusion of CH 3 O 2 NO 2 chemistry results in decreases of up to ~20 % in NO x , ~20 % in N 2 O 5 , ~5 % in HNO 3 , ~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 NO x at low temperatures, CH 3 O 2 NO 2 decreases the cycling of HO 2 to OH, resulting in a larger upper tropospheric HO 2 to OH ratio. These results may impact some estimates of lightning NO x sources as well as help explain differences between models and measurements of upper tropospheric composition.

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