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| Titel |
The tropical forest and fire emissions experiment: laboratory fire measurements and synthesis of campaign data |
| VerfasserIn |
R. J. Yokelson, T. J. Christian, T. G. Karl, A. Guenther |
| 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 ; 8, no. 13 ; Nr. 8, no. 13 (2008-07-04), S.3509-3527 |
| Datensatznummer |
250006268
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| Publikation (Nr.) |
 copernicus.org/acp-8-3509-2008.pdf |
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| Zusammenfassung |
| As part of the Tropical Forest and Fire Emissions
Experiment (TROFFEE), tropical forest fuels were burned in a large,
biomass-fire simulation facility and the smoke was characterized with
open-path Fourier transform infrared spectroscopy (FTIR), proton-transfer
reaction mass spectrometry (PTR-MS), gas chromatography (GC), GC/PTR-MS, and
filter sampling of the particles. In most cases, about one-third of the fuel
chlorine ended up in the particles and about one-half remained in the ash.
About 50% of the mass of non-methane organic compounds (NMOC) emitted by
these fires could be identified with the available instrumentation. The lab
fire emission factors (EF, g compound emitted per kg dry fuel burned) were
coupled with EF obtained during the TROFFEE airborne and ground-based field
campaigns. This revealed several types of EF dependence on parameters such
as the ratio of flaming to smoldering combustion and fuel characteristics.
The synthesis of data from the different TROFFEE platforms was also used to
derive EF for all the measured species for both primary deforestation fires
and pasture maintenance fires – the two main types of biomass burning in
the Amazon. Many of the EF are larger than those in widely-used earlier
work. This is mostly due to the inclusion of newly-available, large EF for
the initially-unlofted smoldering emissions from residual logs in pastures
and the assumption that these emissions make a significant contribution
(~40%) to the total emissions from pasture fires. The TROFFEE EF
for particles with aerodynamic diameter <2.5 microns (EFPM2.5) is 14.8 g/kg
for primary deforestation fires and 18.7 g/kg for pasture maintenance
fires. These EFPM2.5 are significantly larger than a previous recommendation
(9.1 g/kg) and lead to an estimated pyrogenic primary PM2.5 source for the
Amazon that is 84% larger. New regional budgets for biogenic and
pyrogenic emissions were roughly estimated. Coupled with an estimate of
secondary aerosol formation in the Amazon and source apportionment studies,
the regional budgets suggest that ~5% of the total mass of the
regionally generated NMOC end up as secondary organic aerosol within the
Amazonian boundary layer within 1–3 days. New global budgets confirm that
biogenic emissions and biomass burning are the two largest global sources of
NMOC with an estimated production of approximately 1000 (770–1400) and 500
(250–630) Tg/yr, respectively. It follows that plants and fires may also be
the two main global sources of secondary organic aerosol. A limited set of
emission ratios (ER) is given for sugar cane burning, which may help
estimate the air quality impacts of burning this major crop, which is often
grown in densely populated areas. |
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