Seawater and nonseawater aerosol components in the marine atmosphere of Samoa
Two multi-element aerosol components and a third fine particle sulfur component have been identified in the marine atmosphere of Samoa based on elemental composition, time variation and particle size distribution characteristics. On the basis of Pixe (proton induced X ray emission) analyses of 34 cascade impactor samples (17 simultaneous pairs), each of six particle size fractions, collected at 50 m height, July 16 to September 20, 1976, the components are (1) Cl, Br, K, and Sr in >0.5 ..mu..m aerodynamic diameter particles, Ca in 0.5-4 ..mu..m particles, and S in >1 ..mu..m particles, in proportions resembling, but not identical to, seawater composition; (2) a nonseawater component in >4 ..mu..m particles, consisting of 80% of the Ca and median weight ratios for excess Ca/Zn = 3.4, Cu/Zn = 0.11, Ti/Pb = 1.0, Ti/Zn = 0.06, and Fe/Zn = 0.24; (3) S in <1 ..mu..m particles with a geometric mean concentration of 63(1.15) ng/m/sup 3/, comparable to coarse mode S concentrations and similar to values found elsewhere in the southern hemisphere. A wind speed bias against sampling >4 ..mu..m particles during prevailing 1-15 m/s winds was evaluated for K, Cl, and S, indicating zero wind speed >4 ..mu..m concentrations for component (1) to be on the average 2.0 times greater than measured. Differences in processes for transfer of the elements through the sea surface to jet and film drops may account for the observations.
- Research Organization:
- Department of Oceanography, Florida State University, Tallahassee,
- OSTI ID:
- 6320236
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 86:C4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Aerosol characteristics and sources for the Amazon basin during the wet season
The distribution of lead between sea salt, dust, and lead-rich aerosols in the mid South Pacific Easterlies at American Samoa