Skip to content

Cloud condensation nuclei activity of fresh primary and aged biomass burning aerosol

by G. J. Engelhart, C. J. Hennigan, M. A. Miracolo, A. L. Robinson, S. N. Pandis
Atmospheric Chemistry and Physics ()
Get full text at journal


We quantify the hygroscopic properties of particles freshly emitted from biomass burning and after several hours of photochemical aging in a smog chamber. Values of the hygroscopicity parameter, kappa, were calculated from cloud condensation nuclei (CCN) measurements of emissions from combustion of 12 biomass fuels commonly burned in North American wildfires. Prior to photochemical aging, the kappa of the fresh primary aerosol varied widely, between 0.06 (weakly hygroscopic) and 0.6 (highly hygroscopic). The hygroscopicity of the primary aerosol was positively correlated with the inorganic mass fraction of the particles. Photochemical processing reduced the range of kappa values to between 0.08 and 0.3. The changes in kappa were driven by the photochemical production of secondary organic aerosol (SOA). SOA also contributed to growth of particles formed during nucleation events. Analysis of the nucleation mode particles enabled the first direct quantification of the hygroscopicity parameter kappa for biomass burning SOA, which was on average 0.11, similar to values observed for biogenic SOA. Although initial CCN activity of biomass burning aerosol emissions are highly variable, after a few hours of photochemical processing kappa converges to a value of 0.2 +/- 0.1. Therefore, photochemical aging reduces the variability of biomass burning CCN kappa, which should simplify analysis of the potential effects of biomass burning aerosol on climate.

Cite this document (BETA)

Readership Statistics

62 Readers on Mendeley
by Discipline
40% Environmental Science
37% Earth and Planetary Sciences
13% Chemistry
by Academic Status
34% Student > Ph. D. Student
24% Researcher
13% Student > Master
by Country
8% United States
3% United Kingdom
3% Brazil

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in