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...
Published in: | Atmospheric Chemistry and Physics |
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Main Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2011
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Subjects: | |
Online Access: | https://doi.org/10.5194/acp-11-4209-2011 https://doaj.org/article/b0fc51c8e1774458b9048fc4d4ed8115 |
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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