Measurement and Identification of Aerosols Collected Near Barrow, Alaska
Measurements of the concentrations of Aitken nuclei in maritime air were made near Barrow, Alaska, in June 1975 with a modified Nolan-Pollack small-particle detector. The concentrations varied from 50 to 300 particles /cc depending upon meteorological conditions. The mean Aitken nuclei count was 100...
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| Format: | Text |
| Language: | English |
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1978
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| Online Access: | http://www.dtic.mil/docs/citations/ADA058606 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA058606 |
| Summary: | Measurements of the concentrations of Aitken nuclei in maritime air were made near Barrow, Alaska, in June 1975 with a modified Nolan-Pollack small-particle detector. The concentrations varied from 50 to 300 particles /cc depending upon meteorological conditions. The mean Aitken nuclei count was 100 particles /cc for diameters greater than .002 micrometers. Transmission electron micrographs of aerosols in maritime air near Barrow were taken. The size range was measured to be 0.01 to 2.5 micrometers in diameter with the most frequently observed diameter being 0.04 micrometers. The volume of the maritime air and the collection efficiency of aerosol particles on filmed grids for electron microscopy were measured. The aerosol concentrations were found to be 76 to 101 particles /cc; the mean concentration was calculated to be 87 particles /cc. The aerosol particles in the maritime air were identified by electron microscopy and selected area electron diffraction analysis. About 20% of the aerosol particles were identified, and 80% of the particles were too small for electron diffraction analysis. Sea salt particles constituted 2% of the total, and clay minerals 3%; these particles were considered to be of natural origin. Solid combustion by-products such as coagulated carbon particles and flyash particles constituted 16%. Despite the comparative remoteness of the sampling site, the measurements indicate that many anthropogenic aerosols were found using an electron microscope. (Author) |
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