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Marjut Rajasilta Mikael Elfving Jari Hänninen Päivi Laine Ilppo Vuorinen Jorma Paranko 《Ambio》2016,45(2):205-214
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The Baltic Sea runoff events during 1970–2000 were analysed with non-linear estimation in order to find potential stability
and time-varying (non-constancy) properties of time series parameters. In the Baltic Sea area, the wintertime rainfall is
expected to increase, especially in the northern parts of the watershed; furthermore, seasonality is expected to decrease,
i.e. the runoffs will become more evenly distributed over seasons, mainly by decreasing springtime peaks. We found a general
increase in runoffs over the time period studied that consisted of a level shift upwards during the early 1980s. The runoffs
considerably resulted from inputs in the months of April to June (which points to the significance of winter precipitation)
and are biased to northern parts of the catchment. Our results suggest that this is connected with snow and ice melting in
the northern areas of the watershed, especially in the subarctic catchment area of the Neva River (the area includes, for
example, three of the four biggest lakes in Europe, Lake Ladoga, Lake Onega and Lake Saimaa, which are annually covered by
ice). The yearly variation in runoff is significantly stabilised by large N–S extension of the watersheds of these lakes.
The results are generally in accordance with the presented climatic expectations; however, decreasing seasonality was not
obvious in the series yet. However, we found potential implications of system change towards decreased seasonality. By better
understanding of ongoing processes in the sea, the results can give us an opportunity to better evaluate the system control,
predicted areal consequences and ecosystem effects of the climate change. The analysis proved to be a sensitive tool for studying
climatic variation in a relatively small area and over a short time span. 相似文献
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Olli Manilla Tari Haahtela Harri Vaittinen Ilppo Silakoski Olavi Suominen 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1093-1096
We studied the indoor penetration of ambient air malodorous sulfur compounds released by pulp mills. The indoor and outdoor concentrations were simultaneously measured with automatic SO2 analyzers. The filtering effect of three different materials connected to a gaseous filter unit was tested during six study periods. The tested materials were Sorbixofil® based on gypsum impregnated by KMnO4 Purafil® based on Al2O3, both absorbing sulfur compounds by oxidation, and carbonized tissue. The periods lasted from 14 to 88 days. The results indicated that malodorous sulfur air pollutants penetrated indoors effectively, but after some delay because the dilution was slow. In a comparison of different filter materials, Purafil® was the most effective, producing low indoor concentrations. The study concludes that people living near pulp mills are exposed to substantial amounts of malodorous air pollutants, both indoors and outdoors. This exposure can be reduced by using gaseous sulfur sensitive filter materials connected to a controlled ventilation system. 相似文献
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