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| Titel |
Ozone photochemistry in boreal biomass burning plumes observed during the BORTAS aircraft measurement campaign |
| VerfasserIn |
Mark Parrington, Paul Palmer, Ally Lewis, James Lee, Andrew Rickard, Piero Di Carlo, Jonathan Taylor, James Hopkins, Shalini Punjabi, David Oram, Grant Forster, Eleonora Aruffo, Sarah Moller, Stephane Bauguitte, James Allan, Hugh Coe, Roland Leigh |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250073056
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| Zusammenfassung |
| We present an analysis of ozone photochemistry observed in boreal biomass burning plumes
over eastern Canada in the summer of 2011. Measurements of ozone and a number of key
chemical species associated with ozone photochemistry, including non-methane
hydrocarbons (NMHCs), nitrogen oxides (NOx) and total nitrogen containing species
(NOy), were made from the UK FAAM BAe-146 research aircraft as part of the
quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic
using Aircraft and Satellites (BORTAS) experiment between 12 July and 3 August
2011. We show that ozone mixing ratios measured in biomass burning plumes were
indistinguishable from non-plume measurements, but comparison against measurements
of carbon monoxide (CO), total alkyl nitrates (ΣAN) and a surrogate species for
photo-oxidation of NOx (NOz = NOy - NOx) revealed that the potential for ozone
production increased with plume age. We calculated photochemical ages, from
NMHC ratios, for the plumes sampled during BORTAS to range from 0 to 15 days.
Ozone production, calculated from ΔO3/ΔCO enhancement ratios, increased from
0.020 ± 0.008Â ppbv ppbv-1 in plumes with photochemical ages less than 2 days to
0.55 ± 0.29Â ppbv ppbv-1 in plumes with photochemical ages greater than 5 days. In
comparing ozone mixing ratios with components of the NOy budget we show that plumes
with ages between 2 and 4 days were characterised by high aerosol loading, relative humidity
greater than 40%, and low ozone production efficiencies of 8Â ppbv ppbv-1 relative to
ΣAN and 2 ppbv ppbv-1 relative to NOz. In plumes with ages greater than 4 days,
ozone production efficiency was increased to 473 ppbv ppbv-1 relative to ΣAN and
155Â ppbv ppbv-1 relative to NOz. We present the observed plume ozone photochemistry in
relation to other geophysical parameters measured from the aircraft and previous
measurement campaigns that sampled boreal biomass burning plumes over the same region. |
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