Aircraft-based measurements of sulfur dioxide, acetone, carbon dioxide, and condensation nuclei (CN) were made over the north-eastern Atlantic at upper tropospheric altitudes, around 9000 m. On October 14, 1993, strong SO 2- and acetone-pollution (both up to 3 ppbv) were observed, which were accompanied by a CO 2-enhancement of up to 6 ppmv, and large CN-concentrations of up to about 1500 cm -3 (for radii ≥ 6 nm). CN, excess CO 2, and to a lesser degree also acetone, were positively correlated with SO 2. Air mass trajectory analyses indicate, that most of the air masses encountered by our aircraft originated from the polluted planetary boundary layer of the North-Eastern U. S. approximately 4-5 days prior to our measurements, and that polluted boundary layer air experienced fast vertical transport to the upper troposphere as well as horizontal transport across the Atlantic. From our data we conclude, that in the polluted air mass around 9000 m altitude HO x-formation, photochemical SO 2-conversion to gaseous H 2SO 4, and eventually also CN-formation by homogeneous bimolecular (H 2SO 4-H 2O) nucleation may have taken place with enhanced efficiency.
F. Arnold et al., "Observation of Upper Tropospheric Sulfur Dioxide- and Acetone-Pollution: Potential Implications for Hydroxyl Radical and Aerosol Formation," Geophysical Research Letters, vol. 24, no. 1, pp. 57-60, Wiley-Blackwell, Jan 1997.
The definitive version is available at http://dx.doi.org/10.1029/96GL03693
Keywords and Phrases
Acetone; Atmospheric Movements; Boundary Layers; Carbon; Carbon Dioxide; Meteorology; Pollution; Sulfur; Sulfur Dioxide; Troposphere; Acetone; Air Pollution; Atmospheric Aerosols; Carbon Dioxide; Sulfur Dioxide; Aerosol Formation; Air Mass Trajectories; Boundary Layer Air; Condensation Nuclei; Enhanced Efficiency; Horizontal Transport; Planetary Boundary Layers; Vertical Transports; Fighter Aircraft; Atmospheric Chemistry; Aircraft-based Measurements; Observation
International Standard Serial Number (ISSN)
Article - Journal
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