Sulfate aerosol concentrations in the stratosphere have been measured for 11 years (1971–1981) using portions of filters collected by the Department of Energy's High Altitude Sampling Program. Data collected seasonally at altitudes between 13 km and 20 km spanning latitudes from 75°N to 51°S are reported. These data are compared with the reported altitudes of volcanic eruption plumes during the same decade. From this comparison it is concluded that (1) several unreported volcanic eruptions or eruptions to altitudes higher than reported did occur during the decade, (2) the e‐fold removal time for sulfate aerosol from the stratosphere following the eruption of Volcan Fuego in 1974 was 11.2±1.2 months, (3) the volcanic contribution to the average stratospheric sulfate concentration over the decade was greater than 50%, and (4) there may be evidence for an anthropogenic contribution to stratospheric sulfate that increases at the rate of 6 to 8% per year.
The chemical composition of atmospheric particulate matter and rock samples collected on the island of Heimaey after the January 1973 eruption indicates that volcanic activity is a possible source of global significance for particulate material containing elements such as Br, Se, Sb, and Zn. Atmospheric aerosols from such remote areas as the North Atlantic Ocean and the South Pole are found to be highly enriched in these elements.
Measurements of the isotopic composition of methane in the Antarctic atmosphere have indicated the presence of either 12CD4 or 13CHD3. The concentration is about 1.3 × 10−16(v/v). This concentration is at least 500 times higher than expected from the statistical combination of the natural isotopic abundances of H, D, 12C and 13C. There are no known sources of these species large enough to explain these concentrations. It is possible that these species have accumulated in the atmosphere by virtue of having atmospheric residence times that are substantially longer than the residence time of CH4.
The gas permeabilities of more than 20 polymers were measured using pure and mixed gas techniques. The motivation was to determine potential materials that could be used to protect hydrogen getter particles from poisons while permitting sufficient hydrogen rates to enable the getters use in TRUPACT types of containers. A rate of five barrers or larger is needed. Of the materials screened in the pure gas tests, more than 15 qualified. Nine materials qualified in the mixed gas tests, but of the nine only three had high CCl 4 rejection rates and four others would greatly reduce the transport of the CCl 4 .TRUPACT-II to minimize the potential for loss of containment during transport (1). This limit is set at the lower explosive limit of 5 vol % of hydrogen in air. Hydrogen gas generation and accumulation are the result of alpha radiolysis of hydrogenous waste and packaging materials coupled within waste packaging configurations. One method to prevent hydrogen buildup is to employ a hydrogen getter within the containers.
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