Global monitoring at the United States baseline stations with emphasis on precipitation chemistry measurements

The National Oceanic and Atmospheric Administration Geophysical Monitoring for Climatic Change program has operated four remote precipitation chemistry stations at two polar and two tropical Pacific locations for over a decade. Station geography and meteorology is discussed and a summary of the hydrogen, sulfate, and nitrate ion data collected since 1980 is presented. Results show that at all four locations, the ions which have major anthropogenic sources were far less concentrated than in samples collected in heavily industrialized areas in the northeastern United States and Europe. Concentrations at American Samoa and the South Pole showed little variability over the year whereas concentrations at Point Barrow, Alaska and Mauna Loa, Hawaii were highly variable.Contribution from Fourth World Wilderness Congress-Acid Rain Symposium, Denver (Estes Park), Colorado, September 11–18, 1987.     

Background precipitation chemistry monitoring in the Soviet Union

An overview is given of the precipitation chemistry field and laboratory programs of the former U.S.S.R. World Meteorological Organization Background Air Pollution Monitoring Program (WMO BAPMoN). Field and laboratory procedures are discussed, siting criteria are examined, station histories are documented, and four Soviet quality assurance techniques are discussed. Comparison of data from three Soviet BAPMoN stations with data from three U.S. BAPMoN stations indicate that sulfate concentrations are comparable but that U.S. samples are typically much more acidic. Soviet samples tend to have higher concentrations of cations of soil origin and higher concentrations of ammonium.     

The potential for anaerobic mineralisation of hydrocarbon constituents of oily drill cuttings from the North Sea seabed

The potential for natural attenuation of hydrocarbons in oily drill cuttings from the seabed beneath a North Sea oil platform was investigated. The study focused on the anaerobic degradation of n-hexadecane, n-octacosane and naphthalene using additions of 14C-labelled analogues to drill cuttings samples and was conducted under realistic seabed conditions (except pressure) over an 11-month period. No mineralisation of naphthalene was detected over this time period and mineralisation of octacosane represented only 0.5-1.5% of the added label. In contrast, mineralisation of hexadecane was 10-49% after 11 months of incubation. Selective inhibition of key functional bacterial groups revealed the key role of both sulfate reduction and methanogenesis in the degradation process. This study demonstrates the potential for natural attenuation of at least some hydrocarbon constituents of oily drill cuttings under realistic environmental conditions and highlights the involvement of a wide functional consortium in the natural attenuation process.