Marine aerosol chemistry at Cape Grim, Tasmania, and Townsville, Queensland
During September 1979, aerosol samples were collected at two coastal sites in the southern hemisphere: Cape Grim, Tasmania, in the southern temperate latitudes, and Townsville, Queensland, in the subtropical region. Cascade impactors and stacked filter units were used for sampling. The samples were analyzed for the light elements (6< or =Z< or =19) by proton elastic scattering analysis (PESA) and for the heavier elements (Z> or =12) by PIXE. As anthropogenic and continental influence are essentially nonexistent along the track of airmasses for several days before they reach Cape Grim, this site is ideally suited for the study of purely marine airmasses. Sulfur at this site is dominted by seasalt, and the submicron sulfur particle mode universally encountered in the southern tropics and the northern hemisphere is almost not detecable here. It can be shown, however, that sulfur in excess of the amount accounted for by seasalt is present in all size fractions. Calcium appears enriched relative to seasalt on all particle sizes. Chlorine shows no net depletion: there may be chlorine enrichment on the intermediate particle sizes combined with losses on the largest and finest particles. Light element analysis of the submicron aerosol showed significant amounts of organic carbon (approx.0.3 ..mu..g/m/sup 3/): black soot carbon was not visible in samples from Cape Grim during clean air conditions. Stoichiometric relationships between the light elements suggest that most of the nitrogen and sulfur are present in the form of ammonium sulfate. At Townsville, periods of strong continental influence alternated in the synoptic cycle with marine dominated airmasses. Evidence of biomass burning was present in the form of elevated concentrations of submicron potassium and of soot carbon.
- Research Organization:
- Department of Oceanography, Florida State University, Tallahassee, Florida 32306
- OSTI ID:
- 6572807
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 87:C11
- Country of Publication:
- United States
- Language:
- English
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In situ carbon 13 and oxygen 18 ratios of atmospheric CO{sub 2} from Cape Grim, Tasmania, Australia: 1982-1993
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Related Subjects
AEROSOLS
CHEMICAL COMPOSITION
AMMONIUM SULFATES
AUSTRALIA
COASTAL REGIONS
PARTICLE SIZE
SOOT
SURFACE AIR
AIR
AMMONIUM COMPOUNDS
AUSTRALASIA
COLLOIDS
DISPERSIONS
FLUIDS
GASES
OXYGEN COMPOUNDS
SIZE
SOLS
SULFATES
SULFUR COMPOUNDS
500100* - Environment
Atmospheric- Basic Studies- (-1989)