Klimaaenderung und Unterweserregion (KLIMU) 'Fallstudie Weseraestuar'. Teilprojekt: Hydrographisch-oekologische Simulation des Systems Unterweser fuer verschiedene Klimaszenarien (Unterweser-Simulation) Abschlussbericht

The interdisciplinary project 'Climate Change and Lower Weser Region (KLIMU)' aimed at the impact assessment of a presumed climate change and the potential socio-economic and coastal protection responses on the Lower Weser region and provided a basic approach for decision making regarding water management, environmental policies, socio-economy and precautionary planning. In the above mentioned part of the project the impact of the scenarios on hydrography and water quality of the inner Weser estuary was estimated considering the estuary's utilization. In the climate scenario the given rise in water level at the seaward boundary (about 10 km down stream of Bremerhaven, high water +70 cm, low water +40 cm) propagated upstream only with slight deviations. These changes would require coastal protection measures and would have negative impact on the drainage of the marshes. Problems with marsh irrigation could arise from the small upstream displacement of the brackish water zone. The increase in eulittoral was assessed to be ecological positive. The increase in temperature of about 3 C and the hydrodynamical changes affected the strength of the nutrient maxima and the oxygen minimum. The estuary's utilization as a receiving body for waste heat could have to be further restricted. (orig.)SIGLEAvailable from TIB Hannover: F02B918 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany); DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Bonn (Germany)DEGerman

Baltic Sea wave conditions under climate change scenarios

Anthropogenic climate change can alter the wind- and sea-ice climate and thus the wave conditions in the Baltic Sea. Here, transient simulations with the 3rd generation wave model WAM under two IPCC AR4 emission scenarios (A1B and B1) and two initial conditions of the forcing atmospheric fields are analyzed for the period 1961–2100. Future changes in the wave climate comprise higher significant wave height for most regions and simulations. Median waves show temporal and spatial consistent changes, whereas extreme waves (99th percentile and maximum) show much more variability in space and among the simulations. These changes in the wave fields result from not only higher wind speeds but also from a shift to more westerly winds, which leads to different fetch and thus to different significant wave height and direction. The multi-decadal and the inter-simulation variability illustrate the uncertainty in the estimation of the climate change signal