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| Titel |
Biomass burning influence on high-latitude tropospheric ozone and reactive nitrogen in summer 2008: a multi-model analysis based on POLMIP simulations |
| VerfasserIn |
S. R. Arnold, L. K. Emmons, S. A. Monks, K. S. Law, D. A. Ridley, S. Turquety, S. Tilmes, J. L. Thomas, I. Bouarar, J. Flemming, V. Huijnen, J. Mao, B. N. Duncan, S. Steenrod, Y. Yoshida, J. Langner, Y. Long |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 11 ; Nr. 15, no. 11 (2015-06-03), S.6047-6068 |
| Datensatznummer |
250119784
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| Publikation (Nr.) |
 copernicus.org/acp-15-6047-2015.pdf |
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| Zusammenfassung |
| We have evaluated tropospheric ozone enhancement in air dominated by biomass
burning emissions at high latitudes (> 50° N) in July 2008, using
10 global chemical transport model simulations from the POLMIP multi-model
comparison exercise. In model air masses dominated by fire emissions,
ΔO3/ΔCO values ranged between 0.039 and 0.196 ppbv ppbv−1
(mean: 0.113 ppbv ppbv−1) in freshly fire-influenced air, and between 0.140
and 0.261 ppbv ppbv−1 (mean: 0.193 ppbv) in more aged fire-influenced air.
These values are in broad agreement with the range of observational
estimates from the literature. Model ΔPAN/ΔCO enhancement
ratios show distinct groupings according to the meteorological data used to
drive the models. ECMWF-forced models produce larger ΔPAN/ΔCO
values (4.47 to 7.00 pptv ppbv−1) than GEOS5-forced models (1.87 to 3.28 pptv ppbv−1),
which we show is likely linked to differences in efficiency of
vertical transport during poleward export from mid-latitude source regions.
Simulations of a large plume of biomass burning and anthropogenic emissions
exported from towards the Arctic using a Lagrangian chemical transport model
show that 4-day net ozone change in the plume is sensitive to differences in
plume chemical composition and plume vertical position among the POLMIP
models. In particular, Arctic ozone evolution in the plume is highly
sensitive to initial concentrations of PAN, as well as oxygenated VOCs
(acetone, acetaldehyde), due to their role in producing the peroxyacetyl
radical PAN precursor. Vertical displacement is also important due to its
effects on the stability of PAN, and subsequent effect on NOx abundance. In
plumes where net ozone production is limited, we find that the lifetime of
ozone in the plume is sensitive to hydrogen peroxide loading, due to the
production of HOx from peroxide photolysis, and the key role of
HO2 + O3 in controlling ozone loss. Overall, our results suggest
that emissions from biomass burning lead to large-scale photochemical
enhancement in high-latitude tropospheric ozone during summer. |
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