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Latitudinal distribution of black carbon soot in the upper troposphere and lower stratosphereBlack carbon soot from the upper troposphere and lower stratosphere has been systematically collected at latitudes from 90 deg N to 45 deg S. The measured latitudinal distribution of this soot at 10 to 11 km altitude is found to covary with commercial air traffic fuel use, suggesting that aircraft fuel combustion at altitude is the principal source. In addition, at latitudes where the commercial air traffic is high, measured black carbon soot values are high even at 20 km altitude, suggesting that aircraft-generated soot injected just above the tropopause may be transported to higher altitudes. During the volcanically influenced period in which these samples were collected, the number abundances, total mass, and calculated total surface area of black carbon soot are 2-3 orders of magnitude lower than similar measures of sulfuric acid aerosol. During volcanically quiescent periods, the calculated total surface area of black carbon soot aerosol is of the same order of magnitude as that of the background sulfuric acid aerosol. It appears from this comparison that black carbon soot is only capable of influencing lower stratosphere or upper troposphere chemistry during periods when the aerosol budget is not dominated by volcanic activity. It remains to determine the extent to which black carbon soot particles act as nuclei for sulfuric acid aerosol formation. However, mass balance calculations suggest that aircraft soot injected at altitude does not represent a significant source of condensation nuclei for sulfuric acid aerosols.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Blake, David F.
(NASA Ames Research Center Moffett Field, CA United States)
Kato, Katharine
(Search for Extraterrestrial Intelligence Inst. Mountain View, CA United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1995
Publication Information
ISSN: 0148-0227
Subject Category
Environment Pollution
Report/Patent Number
NAS 1.26:199992
Accession Number
Distribution Limits
Public Use Permitted.
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