1. Page 1 Storm issues and results of the past 10 years of work Hans von Storch Institute of Coastal Research, GKSS Research Center, Geesthacht and CLISAP KlimaCampus, Hamburg University, Germany 8. September 2010 - GKSS-Seminar on Storm Studies, Seewetteramt Hamburg

2. Key questions When referring to storms, we refer to wind storms, in particular - Baroclinic midlatitude storms - mesoscale non-tropical storms: polar lows, med sea mesoscale storms - tropical storms (SE Asia/NW Pacific) Relevant variables: strong wind, pressure, impact on coastal ocean We ask for statistics - of present conditions and impacts - recent and current changes of trends (incl. detection and attribution) - scenarios of possible future changes. Page 2

3. Page 3 Message Storminess is best represented by wind statistics, possibly derived quantities such as stream function or vorticity. a)The major problem for statistical analysis of observational wind data is the sampling assumption; such data are almost always inhomogeneous and too short. b)Alternative: proxies – pressure based, sedimentation c)Simulation data are usually “better” – namely homogenous are available for long even very long times. But the degree of realism is always an issue.

4. Page 4 Wind speed measurements  SYNOP Measuring net (DWD)  Coastal stations at the German Bight  Observation period: 1953-2005 Representativity of near surface wind speed measurements This and the next 2 transparencies: Janna Lindenberg, GKSS

5. Page 5 Causes of inhomogenities: Changes in  Instruments  Sampling frequencies  Measuring units  Environments (e.g. trees, buildings)  Location Station relocations (Dotted lines) Representativity of near surface wind speed measurements 1.25 m/s

6. Page 6 Representativity of near surface wind speed measurements

7. Page 7 “Great Miami”, 1926, Florida, Alamaba – damages of 2005 usage - in 2005 money: 139 b$ Katrina, 2005: 81 b$ Pielke, Jr., R.A., Gratz, J., Landsea, C.W., Collins, D., Saunders, M., and Musulin, R., 2008. Normalized Hurricane Damages in the United States: 1900-2005. Natural Hazards Review The increase in damages related to extreme weather conditions is massive – but is it because the weather is getting worse? Losses from Atlantic Hurricanes

8. Key publication Page 8 Polar lows Zahn, M., and H. von Storch, 2008: A longterm climatology of North Atlantic Polar Lows. Geophys. Res. Lett., 35, L22702, doi:10.1029/2008GL035769 Zahn, M., and H. von Storch, 2008: Tracking Polar Lows in CLM, M Zahn, M., H. von Storch, and S. Bakan, 2008: Climate mode simulation of North Atlantic Polar Lows in a limited area model, Tellus A, DOI: 10.1111/j.1600-0870.2008.00330.xeteor. Z. 17: 445-453 Chen, F., 2010: Case study on North Pacific Ocean polar lows in a Regional Climate Model, in preparation Typhoons Feser, F.,and H. von Storch, 2008: Regional modelling of the western Pacific typhoon season 2004, Meteor. Z. 17, 519-528. doi 10.1127/0941-2948/2008/0282Feser, F., and H. von Storch, 2008: A dynamical downscaling case study for typhoons in SE Asia using a regional climate model. Mon. Wea. Rev. 136, 1806-1815 Historical variability Fischer-Bruns, I., H. von Storch, F. González-Rouco and E. Zorita, 2005: Modelling the variability of midlatitude storm activity on decadal to century time scales. Clim. Dyn. 25: 461-476, DOI 10.1007/s00382-005-0036-1 Inhomogeneity Lindenberg, J., H.-T. Mengelkamp and G. Rosenhagen, 2010: Representativity of near surface wind measurements from coastal stations at the German Bight, submitted

9. Page 9 Proxy pressures Schmidt, H. and H. von Storch, 1993: German Bight storms analyzed. Nature 365, 791 Bärring, L. and H. von Storch, 2004: Northern European Storminess since about 1800. Geophys. Res. Lett. 31, L20202, doi:10.1029/2004GL020441, 1-4 Krueger, O., und H. von Storch, 2010: Evaluation of an air pressure based proxy for storm activity, submitted Matulla, C., M. Hofstätter, I. Auer, R. Böhm, H. von Storch and M. Maugeri, 2010 Storminess in Northern Italy and the Adriatic Sea reaching back to 1760, submitted Matulla, C., and H. von Storch, 2009: Changes in Eastern Canadian Storminess since 1880. J. Climate, submitted Baroclinic storms and impacts Günther, H., W. Rosenthal, M. Stawarz, Carretero, J.C., M. Gomez, I. Lozano, O. Serano and M. Reistad, 1998: The wave climate of the Northeast Atlantic over the period 1955-1994: The WASA wave hindcast. Global Atm. Oc. System,6, 121-163 WASA, 1998: Changing waves and storms in the Northeast Atlantic? - Bull. Amer. Met. Soc. 79, 741-760 Weisse, R., H. von Storch and F. Feser, 2005: Northeast Atlantic and North Sea storminess as simulated by a regional climate model 1958-2001 and comparison with observations. J. Climate 18, 465-479 Weisse, R., H. von Storch, U. Callies, A. Chrastansky, F. Feser, I. Grabemann, H. Günther, A. Plüss, T. Stoye, J. Tellkamp, J. Winterfeldt and K. Woth, 2009: Regional meteo-marine reanalyses and climate change projections: Results for Northern Europe and potentials for coastal and offshore applications, Bull. Amer. Meteor. Soc. 90: 849-860. http://dx.doi.org/10.1175/2008BAMS2713.1 Woth, K., R. Weisse and H. von Storch, 2005: Dynamical modelling of North Sea storm surge extremes under climate change conditions - an ensemble study. Ocean Dyn. 56/1: 3-15, DOI 10.1007/s10236-005-0024-3 Grabemann, I. and R. Weisse, 2007: Climate change impact on extreme wave conditions in the North Sea: An ensemble study, Ocean Dynamics, Weisse, R. and A. Plüß, 2005: Storm related sea level variations along the North Sea Coast as simulated by a high-resolution model 1958-2002, Ocean Dynamics, 56(1), 16-25, DOI: 10.1007/s10236-005-0037-y Woth K., 2005: Projections of North Sea storm surge extremes in a warmer climate: How important are the RCM driving GCM and the chosen scenario? Geophys Res Lett: 32, L22708, doi: 10.1029/2005GL023762

10. Page 10 Gudrun Rosenhagen: Storm analysis investigations of DWD Theo Mengelkamp: The extreme wind climate from observations and model data Iria Costas: Climate Archive Dune (ClimAD): a sedimentological record of wind field variations Sebastian Wagner: Storms in the European Alpine region Oliver Krüger: Evaluation of an air pressure based proxy for storm activity Frederik Schenk: Reconstruction of highly resolved wind fields since 1850 AD for Northern Europe Matthias Zahn: Estimation of future polar low frequency over the North Atlantic Fei Chen: Case studies of polar lows by a regional climate model over the North Pacific Ocean Lan Xia: A Comparison of Two Tracking Methods on Polar Lows Leone Cavicchia: An overview of Mediterranean Sea storms Frauke Feser: Typhoon analysis for the last decades Monika Barcikowska: Satellite-based products usability in typhoon statistics validation