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Title:
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Trends in summer sulphate in Europe
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Author(s):
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Published by:
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Publication date:
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ECN
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1996
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ECN report number:
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Document type:
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ECN-RX--96-038
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Other
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Number of pages:
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Full text:
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29
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Download PDF
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Abstract:
A trend analysis of the sulphate concentration in Europe in the summerhalf year was performed. Data from various measuring networks were analyzed,
but only stations with quality assured sampling methods and a record of more
than ten years were included in the study. The reference year for the trend
is 1978, because in that year most stations started operation. The relatively
dense network in Belgium provided the most valuable data, as evidenced by the
fact that two sites at a distance of only 10 km apart correlated better than
95% over a month. The two sites also show a correlation of better than 90%
over a season with two other stations at distances of 45 and 95 km. The
relative decrease in summer-sulphate at the four stations in Belgium, as
analyzed by linear regression, was 3.3% per year which corresponds to an
absolute decrease of 0.42 mug.m"-3 per year. In The Netherlands the
average yearly decrease in summer-sulphate at two stations was 3.5% (-0.34
mug.m"-3). In other countries stations were further apart or only a single
site was in use, which limits the representativeness of the data. In
northwestern Germany, a region with several monitoring stations, a yearly
averaged decrease of 3.0% occurred. The lower absolute decrease (0.25
mug.m"-3) per year compared to that in the two neighbouring countries
reflects the lower summer-time sulphate concentrations. In the remainder of
Germany the average decrease was 1.6%. In South-Scandinavia the yearly
relative decrease at two sites was 2.6% (0.13 mug.m"-3 absolute). There
was no significant trend in the UK. At the Polish station the levels
increased, it decreased at the Hungarian and Austrian station and remained
constant at the Czechoslovakian site. Reasons for omission of the data from
France from the trend analysis are discussed. 7 figs., 2 tabs., 19 refs.
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