Aerosol and Clouds
Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing
Article first published online: 8 NOV 2005
Copyright 2005 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 110, Issue D21, 16 November 2005
How to Cite
2005), Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing, J. Geophys. Res., 110, D21205, doi:10.1029/2005JD005977., , , , and (
- Issue published online: 8 NOV 2005
- Article first published online: 8 NOV 2005
- Manuscript Accepted: 12 AUG 2005
- Manuscript Revised: 12 JUL 2005
- Manuscript Received: 15 MAR 2005
- organic aerosol;
- black carbon
 Measurements of organic carbon (OC) and black carbon (BC) concentrations over a variety of locations worldwide have been analyzed to infer the spatial distributions of the ratios of OC to BC. Since these ratios determine the relative amounts of scattering and absorption, they are often used to estimate the radiative forcing due to aerosols. An artifact in the protocol for filter measurements of OC has led to widespread overestimates of the ratio of OC to BC in atmospheric aerosols. We developed a criterion to correct for this artifact and analyze corrected OC to BC ratios. The OC to BC ratios, ranging from 1.3 to 2.4, appear relatively constant and are generally unaffected by seasonality, sources, or technology changes, at the locations considered here. The ratios compare well with emission inventories over Europe and China but are a factor of 2 lower in other regions. The reduced estimate for OC/BC in aerosols strengthens the argument that reduction of soot emissions maybe a useful approach to slow global warming.