Black carbon absorption at the global scale is affected by particle-scale diversity in composition

Details

• Journal Title:
  Nature Communications
• Personal Author:
  Fierce, Laura ; Bond, Tami C. ; Bauer, Susanne E. ; Mena, Francisco ; Riemer, Nicole
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office)
• Description:
  Atmospheric black carbon (BC) exerts a strong, but uncertain, warming effect on the climate. BC that is coated with non-absorbing material absorbs more strongly than the same amount of BC in an uncoated particle, but the magnitude of this absorption enhancement (E-abs) is not well constrained. Modelling studies and laboratory measurements have found stronger absorption enhancement than has been observed in the atmosphere. Here, using a particle-resolved aerosol model to simulate diverse BC populations, we show that absorption is overestimated by as much as a factor of two if diversity is neglected and population-averaged composition is assumed across all BC-containing particles. If, instead, composition diversity is resolved, we find E-abs=1-1.5 at low relative humidity, consistent with ambient observations. This study offers not only an explanation for the discrepancy between modelled and observed absorption enhancement, but also demonstrates how particle-scale simulations can be used to develop relationships for global-scale models.
• Keywords:
  Aerosols Atmospheric Chemistry Mathematical Models Soot Atmospheric Chemistry Mathematical Models
• Source:
  Nature Communications 7 (12361)
• DOI:
  https://doi.org/10.1038/ncomms12361
• Pubmed Central ID:
  PMC5025768
• Document Type:
  Journal Article
• Rights Information:
  CC BY
• Compliance:
  PMC
• Main Document Checksum:
  urn:sha-512:1f78d2884545770aee41cec3bbe7e66fb828599d0b329d342af46f9a4881885a762c10f4d653eebf4b4c1c479b586fc23172416d033023f0812d7db641255bf8
• Download URL:
  https://repository.library.noaa.gov/view/noaa/24144/noaa_24144_DS1.pdf
• File Type:
  [PDF - 1.00 MB ]