scholarly journals Variability in climate change simulations affects needed long-term riverine nutrient reductions for the Baltic Sea

AMBIO ◽  
2015 ◽  
Vol 44 (S3) ◽  
pp. 381-391 ◽  
Author(s):  
Arvid Bring ◽  
Peter Rogberg ◽  
Georgia Destouni
2021 ◽  
Vol 1 ◽  
pp. 9
Author(s):  
Fred Sanders ◽  
Hugo Sanders ◽  
Karen Jonkers

Gdansk and the city Haarlem in the Netherlands share a long-term relationship that started with the establishment of Dutch Mennonites in the Vistula delta in the 16th Century. A small city was founded called Holland and these immigrants reclaimed the surrounding delta area. This area of 1,000 km2, with hundreds of small ‘polders’ separated and defended by 17,000 dikes, has become an important agricultural area for the whole of Poland, similar to the Rhine delta in the Netherlands. Despite these civil defense works in the past, both coastlines nevertheless experienced floods: the Dutch southwest coast in 1953, Dutch Rhine riverbank in 1993 and 1995, and Vistula delta recently in 2001. Climate change figures show that both the Polish Gdansk and Dutch Rhine deltas will suffer flooding with sea level rises, with accumulating severe rainfall accompanied by high river levels. Although both the Baltic Sea and the North Sea are next to each other and coupled to the Atlantic Ocean, there are differences in how soon or severely climate change trends, such as seawater level rises and water thrust, become critical. From cross-over analysis it can be concluded that Poland and the Netherlands have a virtually identical approach when it comes to climate change impacts on their current situation. With regard to long-term climate change, the Netherlands is exploring the future in a planned manner with the development of new scenarios for the protection of cities. The enclosure of the Baltic Sea, on the other hand, probably offers more options for exchanging knowledge with neighbor states. In that respect, the Netherlands is more isolated in their situation with the North Sea and its Delta Plan. The situation of Gdansk and Rotterdam is quite similar; these cities can take steps forward by learning from each other’s actions.


1991 ◽  
Vol 24 (3-4) ◽  
pp. 373-383 ◽  
Author(s):  
A. Grimvall ◽  
H. Borén ◽  
S. Jonsson ◽  
S. Karlsson ◽  
R. Sävenhed

The long-term fate of chlorophenols and adsorbable organic halogens (AOX) was studied in two large recipients of bleach-plant effluents: Lake Vättern in Sweden and the Baltic Sea. The study showed that there is a long-distance transport (>100 km) of chloroguaiacols from bleach-plants to remote parts of receiving waters. However, there was no evidence of several-year-long accumulation of chloro-organics in the water-phase. A simple water-exchange model for Lake Vättern showed that the cumulated bleach-plant discharges from the past 35 years would have increased the AOX concentration in the lake by more than 100 µg Cl/l, if no AOX had been removed from the water by evaporation, sedimentation or degradation. However, the observed AOX concentration in Lake Vättern averaged only about 15 µg Cl/l, which was less than the average AOX concentration (32 µg Cl/l) in the “unpolluted” tributaries of the lake. Similar investigations in the Baltic Sea showed that non-point sources, including natural halogenation processes, accounted for a substantial fraction of the AOX in the open sea. The presence of 2,4,6-trichlorophenol in precipitation and “unpolluted” surface waters showed that non-point sources may also make a considerable contribution to the background levels of compounds normally regarded as indicators of bleach-plant effluents.


Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 141-150 ◽  
Author(s):  
T. Soomere ◽  
A. Räämet

Abstract. This study focuses on spatial patterns in linear trends of numerically reconstructed basic wave properties (average and extreme wave heights, wave periods) in the Baltic Sea under the assumption of no ice cover. Numerical simulations of wave conditions for 1970–2007, using the WAM wave model and adjusted geostrophic winds, revealed extensive spatial variations in long-term changes in both average and extreme wave heights in the Baltic Sea but almost no changes in the basinwide wave activity and wave periods. There has been a statistically significant decrease in the annual mean significant wave height by more than 10% between the islands of Öland and Gotland and in the southward sea area, and a substantial increase to the south-west of Bornholm, near the coast of Latvia, between the Åland Archipelago and the Swedish mainland, and between the Bothnian Sea and the Bothnian Bay. Variations in extreme wave heights (defined as the threshold for 1% of the highest waves each year) show similar patterns of changes. In several areas the trends in average and extreme wave heights are different. Such a complicated pattern of changes indicates that (i) different regions of the Baltic Sea basin have experienced widespread but essentially different changes in wind properties and (ii) many seemingly controversial trends and variations established in wave properties at different sites in the recent past may reflect the natural spatial variability in the Baltic Sea wave fields.


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