Skip to Main Content
Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumesAuthor(s): A. A. May; T. Lee; G. R. McMeeking; S. Akagi; A. P. Sullivan; S. Urbanski; R. J. Yokelson; S. M. Kreidenweis
Source: Atmospheric Chemistry and Physics. 15: 6323-6335.
Publication Series: Scientific Journal (JRNL)
Station: Rocky Mountain Research Station
Download Publication (2.0 MB)
DescriptionOpen biomass burning is a significant source of primary air pollutants such as particulate matter (PM) and non-methane organic gases (NMOG). However, the physical and chemical atmospheric processing of these emissions during transport is poorly understood. Atmospheric transformations of biomass burning emissions have been investigated in environmental chambers, but there have been limited opportunities to investigate these transformations in the atmosphere. In this study, we deployed a suite of real-time instrumentation on a Twin Otter aircraft to sample smoke from prescribed fires in South Carolina, conducting measurements at both the source and downwind to characterize smoke evolution with atmospheric aging. Organic aerosol (OA) within the smoke plumes was quantified using an aerosol mass spectrometer (AMS); refractory black carbon (rBC) was quantified using a single-particle soot photometer, and carbon monoxide (CO) and carbon dioxide (CO2/ were measured using a cavity ring-down spectrometer. During the two fires for which we were able to obtain aerosol aging data, normalized excess mixing ratios and "export factors" of conserved species (rBC, CO, CO2/ suggested that changes in emissions at the source did not account for most of the differences observed in samples of increasing age. An investigation of AMS mass fragments indicated that the in-plume fractional contribution (fm=z/ to OA of the primary fragment (m=z 60) decreased downwind, while the fractional contribution of the secondary fragment (m=z 44) increased. Increases in f44 are typically interpreted as indicating chemical aging of OA. Likewise, we observed an increase in the O:C elemental ratio downwind, which is usually associated with aerosol aging. However, the rapid mixing of these plumes into the background air suggests that these chemical transformations may be attributable to the different volatilities of the compounds that fragment to these m=z in the AMS. The gas-particle partitioning behavior of the bulk OA observed during the study was consistent with the predictions from a parameterization developed for open biomass burning emissions in the laboratory. Furthermore, we observed no statistically significant increase in total organic mass with atmospheric transport. Hence, our results suggest that dilution-driven evaporation likely dominated over the chemical production of secondary organic aerosol (SOA) within our smoke plumes, presumably due to the fast dilution and limited aging times (<~5 h) that we could sample.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMay, A. A.; Lee, T.; McMeeking, G. R.; Akagi, S.; Sullivan, A. P.; Urbanski, S.; Yokelson, R. J.; Kreidenweis, S. M. 2015. Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumes. Atmospheric Chemistry and Physics. 15: 6323-6335.
Keywordsfire, smoke, biomass burning, air pollutants, particulate matter (PM), non-methane organic gases (NMOG)
- Measurements of trace gases and particles in fresh and aged smoke from a chaparral fire in California
- Evolution of trace gases and particles emitted by a chaparral fire in California
- Preliminary observations of organic gas-particle partitioning from biomass combustion smoke using an aerosol mass spectrometer
XML: View XML