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| Titel |
Measured and modeled humidification factors of fresh smoke particles from biomass burning: role of inorganic constituents |
| VerfasserIn |
J. L. Hand, D. E. Day, G. M. McMeeking, E. J. T. Levin, C. M. Carrico, S. M. Kreidenweis, W. C. Malm, A. Laskin, Y. Desyaterik |
| 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 ; 10, no. 13 ; Nr. 10, no. 13 (2010-07-09), S.6179-6194 |
| Datensatznummer |
250008610
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| Publikation (Nr.) |
 copernicus.org/acp-10-6179-2010.pdf |
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| Zusammenfassung |
| During the 2006 FLAME study (Fire Laboratory at
Missoula Experiment), laboratory burns of biomass fuels
were performed to investigate the physico-chemical, optical, and hygroscopic
properties of fresh biomass smoke. As part of the experiment, two
nephelometers simultaneously measured dry and humidified light scattering
coefficients (bsp(dry) and bsp(RH), respectively) in order to
explore the role of relative humidity (RH) on the optical properties of
biomass smoke aerosols. Results from burns of several biomass fuels from the
west and southeast United States showed large variability in the
humidification factor (f(RH)=bsp(RH)/bsp(dry)). Values of f(RH) at
RH=80–85% ranged from 0.99 to 1.81 depending on fuel type. We
incorporated measured chemical composition and size distribution data to
model the smoke hygroscopic growth to investigate the role of inorganic
compounds on water uptake for these aerosols. By assuming only inorganic
constituents were hygroscopic, we were able to model the water uptake within
experimental uncertainty, suggesting that inorganic species were responsible
for most of the hygroscopic growth. In addition, humidification factors at
80–85% RH increased for smoke with increasing inorganic salt to carbon
ratios. Particle morphology as observed from scanning electron microscopy
revealed that samples of hygroscopic particles contained soot chains either
internally or externally mixed with inorganic potassium salts, while samples
of weak to non-hygroscopic particles were dominated by soot and organic
constituents. This study provides further understanding of the compounds
responsible for water uptake by young biomass smoke, and is important for
accurately assessing the role of smoke in climate change studies and
visibility regulatory efforts. |
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