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| Titel |
Explaining variance in black carbon's aging timescale |
| VerfasserIn |
L. Fierce, N. Riemer, T. C. Bond |
| 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. 6 ; Nr. 15, no. 6 (2015-03-20), S.3173-3191 |
| Datensatznummer |
250119566
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| Publikation (Nr.) |
 copernicus.org/acp-15-3173-2015.pdf |
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| Zusammenfassung |
| The size and composition of particles containing black carbon (BC) are
modified soon after emission by condensation of semivolatile substances and
coagulation with other particles, known collectively as "aging" processes.
Although this change in particle properties is widely recognized, the
timescale for transformation is not well constrained. In this work, we
simulated aerosol aging with the particle-resolved model PartMC-MOSAIC (Particle Monte Carlo – Model for Simulating Aerosol Interactions and Chemistry) and
extracted aging timescales based on changes in particle cloud condensation
nuclei (CCN). We simulated nearly 300 scenarios and, through a regression
analysis, identified the key parameters driving the value of the aging
timescale. We show that BC's aging timescale spans from hours to weeks,
depending on the local environmental conditions and the characteristics of
the fresh BC-containing particles. Although the simulations presented in this
study included many processes and particle interactions, we show that 80% of
the variance in the aging timescale is explained by only a few key
parameters. The condensation aging timescale decreased with the flux of
condensing aerosol and was shortest for the largest fresh particles, while
the coagulation aging timescale decreased with the total number concentration
of large (D >100 nm), CCN-active particles and was shortest for the smallest
fresh particles. Therefore, both condensation and coagulation play important
roles in aging, and their relative impact depends on the particle size range. |
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