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Titel |
Emissions from biomass burning in the Yucatan |
VerfasserIn |
R. J. Yokelson, J. D. Crounse, P. F. DeCarlo, T. Karl, S. Urbanski, E. Atlas, T. Campos, Y. Shinozuka, V. Kapustin, A. D. Clarke, A. Weinheimer, D. J. Knapp, D. D. Montzka, J. Holloway, P. Weibring, F. Flocke, W. Zheng, D. Toohey, P. O. Wennberg, C. Wiedinmyer, L. Mauldin, A. Fried, D. Richter, J. Walega, J. L. Jimenez, K. Adachi, P. R. Buseck, S. R. Hall, R. Shetter |
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 ; 9, no. 15 ; Nr. 9, no. 15 (2009-08-12), S.5785-5812 |
Datensatznummer |
250007570
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Publikation (Nr.) |
copernicus.org/acp-9-5785-2009.pdf |
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Zusammenfassung |
In March 2006 two instrumented aircraft made the first
detailed field measurements of biomass burning (BB) emissions in the
Northern Hemisphere tropics as part of the MILAGRO project. The aircraft
were the National Center for Atmospheric Research C-130 and a University of
Montana/US Forest Service Twin Otter. The initial emissions of up to 49
trace gas or particle species were measured from 20 deforestation and crop
residue fires on the Yucatan peninsula. This included two trace gases useful
as indicators of BB (HCN and acetonitrile) and several rarely, or never
before, measured species: OH, peroxyacetic acid, propanoic acid, hydrogen
peroxide, methane sulfonic acid, and sulfuric acid. Crop residue fires
emitted more organic acids and ammonia than deforestation fires, but the
emissions from the main fire types were otherwise fairly similar. The
Yucatan fires emitted unusually high amounts of SO2 and particle
chloride, likely due to a strong marine influence on this peninsula. As
smoke from one fire aged, the ratio ΔO3/ΔCO increased
to ~15% in <~1 h similar to the fast net production of
O3 in BB plumes observed earlier in Africa. The rapid change in O3
occurs at a finer spatial scale than is employed in global models and is
also faster than predicted by micro-scale models. Fast increases in PAN,
H2O2, and two organic acids were also observed. The amount of
secondary organic acid is larger than the amount of known precursors. Rapid
secondary formation of organic and inorganic aerosol was observed with the
ratio ΔPM2.5/ΔCO more than doubling in ~1.4±0.7 h.
The OH measurements revealed high initial levels (>1×107 molecules/cm3)
that were likely caused in part by high initial
HONO (~10% of NOy). Thus, more research is needed to
understand critical post emission processes for the second-largest trace gas
source on Earth. It is estimated that ~44 Tg of biomass burned in the
Yucatan in the spring of 2006. Mexican BB (including Yucatan BB) and urban
emissions from the Mexico City area can both influence the March-May air
quality in much of Mexico and the US. |
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