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Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O Full text
1999
Hermans, Christian | Vandaele, Ann C. | Carleer, Michel | Fally, Sophie | Colin, Réginald | Jenouvrier, Alain | Coquart, Bernard | Mérienne, Marie-France
Absorption spectroscopy, which is widely used for concentration measurements of tropospheric and stratospheric compounds, requires precise values of the absorption cross-sections of the measured species. NO₂, O₂ and its collision-induced absorption spectrum, and H₂O absorption cross-sections have been measured at temperature and pressure conditions prevailing in the Earth’s atmosphere. Corrections to the generally accepted analysis procedures used to resolve the convolution problem are also proposed.
Show more [+] Less [-]Distribution of volatile organic compounds in Madrid (Spain) Full text
1999
Pérez-Pastor, Rosa María | García-Alonso, Susana | Cabezas, Alberto José Quejido
From November 1995 to October 1996, airborne concentrations of VOCs were measured in the Madrid area to study the organic pollution in general, and the correlation between different pollutants in relation to such parameters as location and season. Mean concentrations for up to 90 compounds were measured at four test sites, including both urban and suburban areas.At the urban sites, maximum concentrations occurred in the autumn and winter, whereas minimum concentrations were reached in summer and spring. Similar changes were obtained for the lesscontaminated site located in the SE of the city, whereas a different pattern was found at the site in the NW of the city due to meteorological aspects. Mean levels of hydrocarbons in Madrid were quite similar to those found in other European cities.Chemometrical techniques were applied to the set of data in order to assess the influence of such factors as traffic, temperature and seasonal variations on the VOC levels.
Show more [+] Less [-]Anthropogenic platinum fluxes: Quantification of sources and sinks, and outlook Full text
1999
Helmers, Eckard | Kümmerer, Klaus
Employing the data available to date, anthropogenic Pt fluxes are calculated for Germany with special emphasis on the Pt emitted by cars equipped with catalytic converters. Pt fluxes are quantified using five different methods (street deposition, automobile emission rate, sewage sludges, atmospheric load, industrial consumption). During the first and the second methods, approx. 100 kg of emitted Pt are seen to result for both for the mid 1990’s. Up to the year 2018, a total of 2100 kg of Pt will be emitted by cars equipped with catalytic converters. The diffuse atmospheric Pt deposition amounts to 0.73 – 4.4 μg/m²y or 260 kg Pt/year. Industrial sources emitting Pt into the atmosphere are likely but difficult to quantify. The enrichment of Pt in soils during agriculture fertilization with sewage sludges and during diffuse atmospheric deposition result in a level of 46 – 460 ng/kg up to the year 2018. Although this is slightly below the geogenic background, a comparison with the pollution history of Pb implies that forthcoming environmental Pt enrichment should not be neglected.
Show more [+] Less [-]Assessing the effects of international emissions reduction scenarios to combat the acidification of freshwaters in Great Britain with the First-order Acidity Balance (FAB) model and the Hull Acid Rain Model (HARM)
1999
Curtis, C.J. | Whyatt, J.D. | Metcalfe, S.E. | Allott, T.E.H. | Harriman, R.
Effect-based control strategies: what do we need in the future?
1999
Grennfelt, P.
How are results from critical load calculations reflected in lake water chemistry?
1999
Wilander, A. (SLU, Uppsala (Sweden))
Investigation of the uncertainties and assumptions in the Simple Mass Balance equation for acidity critical loads
1999
Hall, J. | Hornung, M. | Kennedy, F. | Langan, S. | Reynolds, B. | Aherne, J.
The link between the exceedance of acidity critical loads for freshwaters and biological damage: a re-interpretation
1999
Curtis, C.J. (ECRC, London (UK)) | Reynolds, B. | Allott, T.E.H. | Harriman, R.
Aluminum biogeochemistry in two Czech catchments with contrasting lithology subject to chronic acidic deposition
1999
Kram, P. | Hruska, J. (Czech Geological Survey, Prague (Czech Republic)) | Driscoll, C.T. | Johnson, C.E.
Can the division sum (Ca + K + Mg divided by Al) ratio be used as a predictive tool for estimating forest damages?
1999
Goeransson, A. (SLU, Uppsala (Sweden))