Title: Brown carbon in tar balls from smoldering biomass combustion
Author: Chakrabarty, R. K.; Moosmuller, H.; Chen, L.-W. A.; Lewis, K.; Arnott, W. P.; Mazzoleni, C.; Dubey, M. K.; Wold, C. E.; Hao, W. M.; Kreidenweis, S. M.
Source: Atmospheric Chemistry and Physics. 10: 6363-6370.
Publication Series: Journal/Magazine Article (JRNL)
Description: We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Angstrom coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent imaginary part of its refractive index - optically defined as "brown carbon" - is an important component of tar balls. The spectrum of the imaginary parts of their complex refractive indices can be described with a Lorentzian-like model with an effective resonance wavelength in the ultraviolet (UV) spectral region. Sensitivity calculations for aerosols containing traditional OC (no absorption at visible and UV wavelengths) and brown carbon suggest that accounting for near-UV absorption by brown carbon leads to an increase in aerosol radiative forcing efficiency and increased light absorption. Since particles from smoldering combustion account for nearly three-fourths of the total carbonaceous aerosol mass emitted globally, inclusion of the optical properties of tar balls into radiative forcing models has significance for the Earth's radiation budget, optical remote sensing, and understanding of anomalous UV absorption in the troposphere.
Keywords: brown carbon, tar balls, UV absorption
- 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.
XML: View XML
Chakrabarty, R. K.; Moosmuller, H.; Chen, L.-W. A.; Lewis, K. ; Arnott, W. P.; Mazzoleni, C.; Dubey, M. K.; Wold, C. E.; Hao, W. M.; Kreidenweis, S. M. 2010. Brown carbon in tar balls from smoldering biomass combustion. Atmospheric Chemistry and Physics. 10: 6363-6370.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility