Aerosol organic carbon to black carbon ratios: Analysis ofpublished data and implications for climate forcing
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 1.3to 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 two 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.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE. Office of Office of Biological and EnvironmentalResearch; National Aeronautical and Space Administration
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 862173
- Report Number(s):
- LBNL-57771; JGREA2; R&D Project: E21001; BnR: 400409900; TRN: US200602%%82
- Journal Information:
- Journal of Geophysical Research, Vol. 110; Related Information: Journal Publication Date: 2005; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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