Norman Dreier, Peter Fröhle, Dörte Salecker, Christian Schlamkow, Xu Zhenshan


On the basis of hourly simulated wind data from a regional circulation model (Cosmo-CLM) wave conditions from 1960 to 2100 are calculated for two realisations each of the global emission scenarios A1B and B1 using a numerical wave model for the area of the Western Baltic Sea. Comparisons of the 30 years averages of the wave conditions between the future and the past show that the changes of the average wave conditions can be directly linked to the changes of the average wind conditions. The changes of the average wave conditions and extreme wave events are characterised by high spatial and annual variability. In addition the changes depend on the time period of the comparison, the global emission scenario and the realisation of the climate model run. The bandwidth of the changes is moreover affected by the approach for the calculation of the wave conditions. A significant climate change signal of the average wave conditions is found at westerly wind exposed locations with predominant higher values of the average significant wave heights up to +10%. At easterly wind exposed locations the climate change signal is more weak and higher and lower values are possible (-5% to +5%). Regarding the future changes of the wave directions, in general more wave events from W-NW and fewer events from N-NE can be expected. Analyses of extreme wave heights with a return period of 200 years show both increasing and decreasing values (-0.5m to +0.5m). The climate change signal of the extreme wave events is, as the same for the changes of the average wave conditions, more robust at locations which are exposed to westerly winds.


Baltic Sea; regional climate change; Cosmo-CLM; SWAN wave model; extreme wave conditions

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BACC. 2008. Assessment of Climate Change for the Baltic Sea Basin. In: Bolle, H.-J., Menenti, M. and Rasool, I. (eds.), Regional Climate Studies, Springer-Verlag Berlin Heidelberg, 2008, ISBN 978-3-540- 72785-9.

Booij, N., Ris, R.C. and Holthuijsen, L.H. 1999. A third-generation wave model for coastal regions. Part I - Model description and validation. Journal of Geophysical Research, 104, C4, 7649-7666.

Coles, S. 2001. An Introduction to Statistical Modelling of Extreme Values. Springer Series in Statistics. Springer Verlag, London, 2001, p. 208

Dreier, N., Schlamkow, C., Fröhle, P. and Salecker, D. 2013. Changes of 21st Century's average and extreme wave conditions at the German Baltic Sea Coast due to global climate change. In: Conley, D.C., Masselink, G., Russell, P.E. and O’Hare, T.J. (eds.), Proceedings 12th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. 1921-1926

Groll, N., Hünicke B. and Weisse, R. 2013. Baltic Sea wave conditions under climate change scenarios. In: Reckermann, M. & Köppen, S. (eds.), Conference Proceedings of the 7th Study Conference on BALTEX (10-14 June 2013, Borgholm, Sweden), International BALTEX Secretariat, Publication No. 53, June 2013, p. 62, ISSN 1681-6471.

Hasselmann, S., Hasselmann, K., Bauer, E., Janssen, P.A.E.M., Komen, G.J., Bertotti, L., Lionello, P., Guillaume, A., Cardone, V.C., Greenwood, J.A., Reistad, M., Zambresky, L. and Ewing, J.A. 1988. The WAM model ¬ a third generation ocean wave prediction model. J. Phys. Oceanogr. 18, 1775-1810.

Lautenschlager, M., Keuler, K., Wunram, C., Keup-Thiel, E., Schubert, M., Will, A., Rockel, B. and Boehm, U. 2009. Climate Simulation with COSMO-CLM. Climate of the 20th Century run no.1-3, Scenario A1B run no.1-2, Scenario B1 run no.1-2 , Data Stream 3: European region MPI-M/MaD. World Data Centre for Climate.

Legutke, S., Hollweg, H.-D., Lautenschlager, M., Fast, I., Hennemuth, B., Keup-Thiel, E., Schubert, M. and Wunram, C. 2009. Transient Ensemble Climate Simulations over Europe with the RCM CLM forced by ECHAM5/MPI-OM IPCC AR4 Experiments. Sub. to Meteorologische Zeitschrift. http://www.clm-

Nakićenović, N., Alcamo, J., Davis, G., de Vries, B., Fenhann, J., Gaffin, S., Gregory, K., Grübler, A., Jung, T.Y., Kram, T., La Rovere, E.L., Michaelis, L., Mori, S., Morita, T., Pepper, W., Pitcher, H., Price, L., Raihi, K., Roehrl, A., Rogner, H.-H., Sankovski, A., Schlesinger, M., Shukla, P., Smith, S., Swart, R., van Rooijen, S., Victor, N. and Dadi, Z. 2000. Emissions Scenarios. A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge and New York, pp. 599

Rockel, B., Will, A. and Hense, A. (eds.) 2008. Special Issue: Regional circulation modelling with COSMO- CLM (CCLM). Meteorologische Zeitschrift, Vol. 17.Experimentation. IAHR Design Manual Series, CRC Press/Balkema, Leiden, The Netherlands.

Roeckner, E., Lautenschlager, M., Schneider, H. 2006. IPCC-AR4 MPI-ECHAM5 T63L31 MPI-OM GR1.5L40 20C3M run no.1: atmosphere 6 hour values MPImet/MaD Germany. World Data Center for Climate, doi: 10.1594/WDCC/EH5-T63L31 OM-GR1.5L40 20C 1 6H.

Schlamkow, C. and Fröhle, P. 2009. Entwicklung von Methoden zur Bestimmung maßgebender hydrodynamischer Bemessungsparameter für Küstenschutzanlagen an der Ostsee, Abschlussbericht 3.1 zum KFKI-Verbundprojekt Modellgestützte Untersuchungen zu extremen Sturmflutereignissen an der deutschen Ostseeküste (MUSTOK). Teilvorhaben SEBOK-B. Rostock, 2009, http://edok01.tib.uni-

Schlamkow, C. , Dreier, N., Fröhle, P. and Salecker, D. 2012. Future extreme waves at the German Baltic Sea Coast derived from regional climate model runs.

Coastal Engineering Proceedings, [S.l.], n. 33, p. management.5, dec. 2012. ISSN 2156-1028. Available at: . Date accessed: 26 Aug. 2014. doi:

Seifert, T., Tauber, F. and Kayser, B. 2001. "A high resolution spherical grid topography of the Baltic Sea – 2nd edition", Baltic Sea Science Congress, Stockholm 25-29. November 2001, Poster #147,

Wilks, D. S. 2011. Statistical methods in the atmospheric sciences. In: Dmowska, R., Hartmann, D. and Rossby, H. T. (eds.), International Geophysics Series, Volume 100, 3rd ed., Academic Press, Elsevier, 2011, 151-154, ISBN 978-0-12-385022-5.