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Stürme und Sturmfluten - Literatur
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Bärring and v. Storch (2004): Northern European Storminess since about 1800
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Behrens (2002): Seegangsvorhersage
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Dankert, Horstmann, Lehner and Rosenthal (2003): Detection of Waves Groups in SAR Images and Radar-Image Sequences
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Feser, Weisse and v. Storch (2001): Multi-decadal Atmospheric Modeling for Europe Yields Multi-purpose Data
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Fischer-Bruns, v. Storch, González-Rouco and Zorita (2005): Modelling the variability of midlatitude storm activity on decadal to century time scales
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Gaslikova and Weisse (2006): Estimating near-shore wave statistics from regional hindcasts using downscaling techniques
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Horstmann and Koch (2005): Measurement of Ocean Surface Winds Using Synthetic Aperture Radars
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Horstmann, Thompson, Monaldo, Graber and Iris (2005): Can Synthetic Aperture Radars be used to Estimate Hurricane Force Winds?
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Koch and Feser (2006): Relationship between SAR-Derived Wind Vectors and Wind at 10-m Height Represented by a Mesoscale Model
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Soomere, Beherens, Tuomi and Nielsen (2005): Unusual wave conditions in the Baltic Proper and in the Gulf of Finland during windstorm Gudrun
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The Wasa Group (1998): Changing waves and storms in the Northeast Atlantic?
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Weisse, v. Storch and Feser (2005): Northeast Atlantic and North Sea storminess as simulated by a regional climate model 1958-2001 and comparison with observations
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Weisse and Pluess (2006): Storm-related sea level variations along the North Sea coast as simulated by a high-resolution model 1958-2002
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Woth (2005): North Sea storm surge statistics based on projections in a warmer climate: How important are the driving GCM and the chosen emission scenario?
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Woth, Weisse and v. Storch (2006): Climate change and North Sea storm surge extremes: An ensemble study of storm surge extremes expected in a changed climate projected by four different Regional Climate Models
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| Titel: |
Northern European Storminess since about 1800 |
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| Autor(en): |
Lars Bärring and Hans von Storch |
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| Veröffentlicht in: |
Geophys. Res. Letters 31, L20202, doi:10.1029/2004GL020441, 1-4 |
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| Abstract: |
We study the history of storminess in Northern Europe, as derived from local pressure observations in Lund since 1780 and Stockholm since 1820 (Sweden). At both stations barometer readings were made three times per day, morning, midday and evening, and after about 1850 at fixed observation hours. We use four common storminess indices: annual number of deep lows (p<980 hPa), the annual 95th and 99th percentile of pressure changes between two observations, and the annual number of fast absolute pressure changes (|Δp|/Δt > 16 hPa/12 h). It turns out that the 1980's - mid 1990's were a period of enhanced storminess, mainly seen in the Stockholm record, but his period is within the natural variability of the records. Thus, there are no robust signs of any long-term trend in the storminess indices. Storminess is during the entire historical period remarkably stable, with no systematic change and little transient variability. |
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| Link: |
http://dx.doi.org/10.1029/2004GL020441 |
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| Titel: |
Seegangsvorhersage |
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| Autor(en): |
A. Behrens |
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| Veröffentlicht in: |
Promet, Deutscher Wetterdienst, Jahrgang 28, Heft 1 / 2 pp 17-23 |
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| Abstract: |
GKSS betreut seit 1981 die Seegangsvorhersage beim Deutschen Wetterdienst. Das aktuelle Vorhersagesystem beruht auf dem Wellenmodell dritter Generation WAM Cycle 4 und liefert seit 1991 Seegangsvorhersagen auf der globalen Skala, als auch regional für Nord- und Ostsee sowie für das Mittelmeer. Der Artikel enthält eine detaillierte Beschreibung des numerischen Vorhersagesystems, inklusive der zugrundeliegenden Gleichungen, der antreibenden Kräfte und der erzielten Ergebnisse. |
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| Link: |
http://www.dmg-ev.de/gesellschaft/publikationen/pdf/promet/pdf_gross/promet_28_12.pdf |
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| Titel: |
Detection of Waves Groups in SAR Images and Radar-Image Sequences |
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| Autor(en): |
H. Dankert, J. Horstmann, S. Lehner, and W. Rosenthal |
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| Veröffentlicht in: |
IEEE Trans. on Geosc. and Remote Sens., Vol. 41, No. 6, 2003 |
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| Abstract: |
The properties of individual wave groups in space and time utilizing synthetic aperture radar (SAR) images and nautical radar-image sequences are studied. This is possible by the quantitative measurement and analysis of wave groups both spatially and spatial-temporally. The SAR, with its high spatial resolution and large coverage, offers a unique opportunity to study and derive wave groups. In addition to SAR images, nautical radar-image sequences allow the investigation of wave groups in space and time and therefore the measurement of parameters such as the group velocity. The detection of wave groups is based on the determination of the envelope function, which was first adopted for 1d-time series by Longuet-Higgins. The method is extended from 1d to spatial and spatio-temporal dimensions to derive wave groups in images and image sequences. To test the algorithm, wave groups are derived from SAR images and two radar-image sequences, recorded at locations in deep and shallow water. It is demonstrated that the algorithm can be employed for the determination of both location and size of wave groups from radar images. Investigating the detected wave groups in radar-image sequences additionally allows the measurement of the spatial and temporal development of wave groups and their extension and phase velocities. Comparison of measured wave group velocities in shallow and deep water gives an agreement of the average value with the group velocities resulting from linear wave theory and shows a clear oscillation of the group velocities in 2d. |
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| Link: |
http://w3g.gkss.de/G/Mitarbeiter/dankert/PDF/TGRS_2003_811815_Heiko_Dankert_600dpi.pdf |
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| Titel: |
Multi-decadal Atmospheric Modeling for Europe Yields Multi-purpose Data |
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| Autor(en): |
Frauke Feser, Ralf Weisse and Hans von Storch |
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| Veröffentlicht in: |
EOS, 82(28), p.305, 2001 |
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| Abstract: |
n. a. |
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| Link: |
http://w3g.gkss.de/staff/feser.html/EOS10017.pdf |
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| Titel: |
Modelling the variability of midlatitude storm activity on decadal to century time scales |
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| Autor(en): |
Irene Fischer-Bruns, Hans von Storch, Fidel González-Rouco and Eduardo Zorita |
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| Veröffentlicht in: |
Clim. Dyn. 25: 461-476, DOI 10.1007/s00382-005-0036-1 |
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| Abstract: |
The output of several multi-century simulations with a coupled Ocean-Atmosphere General Circulation Model is examined with respect to the variability of global storm activity in winter on time scales of decades and longer. The frequency of maximum wind speed events within a grid box, using the lower limits on the Beaufort wind speed scale of 8 and 10 Bft as thresholds, is taken as characteristic parameter. Two historical climate runs with time-dependent forcing of the last five centuries, one control simulation, and three climate change experiments are considered. The storm frequency shows no trend until recently. Global maps for the industrially influenced period do hardly differ from pre-industrial maps, even though significant temperature anomalies temporarily emerge in the historical runs. Two indicators describing the frequency and the regional shift of storm activity are determined. In pre-industrial times they are decoupled from temperature. Variations in solar and volcanic forcing in the historical simulations as well as in greenhouse gas concentrations for the industrially influenced period are not related to variations in storm activity. Also, anomalous temperature regimes like the Late Maunder Minimum are not associated with systematic storm conditions. In the climate change experiments, a poleward shift of storm activity is found in all three storm track regions. Over the North Atlantic and Southern Ocean, storm activity increases, while it decreases over the Pacific Ocean. In contrast to the historical runs, the storm indices parallel the development of temperature, exceeding the 2 σ-range of pre-industrial variations in the early 21st century. |
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| Link: |
http://dx.doi.org/10.1007/s00382-005-0036-1 |
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| Titel: |
Estimating near-shore wave statistics from regional hindcasts using downscaling techniques |
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| Autor(en): |
Lidia Gaslikova and Ralf Weisse |
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| Veröffentlicht in: |
Ocean Dynamics, 56(1), 26-35, 2006, doi:10.1007/s10236-005-0041-2 |
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| Abstract: |
Several downscaling techniques comprising fully dynamical and statistical-dynamical methods applied to near-shore local wave climate are tested and assessed in terms of wave statistics with respect to the added value that can be achieved compared to larger scale data. The techniques are applied for the example of Helgoland, a small island in the German Bight. Comparing the near-shore wave climate it was found that generally an improved representation could be obtained from all downscaling techniques. Based on a balance between the required computer resources and the improvements achieved it is suggested that, to this end, a dynamical-statistical approach based on high-resolution coastal wave modeling and linear regression provides the optimal choice. |
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| Link: |
http://dx.doi.org/10.1007/s10236-005-0041-2 |
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| Titel: |
Measurement of Ocean Surface Winds Using Synthetic Aperture Radars |
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| Autor(en): |
J. Horstmann and W. Koch |
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| Veröffentlicht in: |
IEEE J. Ocean. Eng., Vol. 30, No. 3, 2005 |
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| Abstract: |
A methodology for retrieving high-resolution ocean surface wind fields from satellite-borne synthetic aperture radar (SAR) data is introduced and validated. The algorithms developed are suited for ocean SAR data, which were acquired at the C band of either vertical (VV) or horizontal (HH) polarization in transmission and reception. Wind directions are extracted from wind-induced streaks that are visible in SAR images of the ocean at horizontal scales greater than 200 m. These wind streaks are very well aligned with the mean surface wind direction. To extract the orientation of these streaks, two algorithms are introduced, which are applied either in the spatial or spectral domain. Ocean surface wind speeds are derived from the normalized radar cross section (NRCS) and image geometry of the calibrated SAR images, together with the local SAR-retrieved wind direction. Therefore, several C-band models (CMOD_IFR2, CMOD4, and CMOD5) are available, which were developed for VV polarization, and have to be extended for HH polarization. To compare the different algorithms and C-band models as well as demonstrate their applicability, SAR-retrieved wind fields are compared to numerical-model results considering advanced SAR (ASAR) data from Environmental Satellite (ENVISAT), a European satellite. |
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| Link: |
http://dx.doi.org/10.1109/JOE.2005.857514 |
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| Titel: |
Can Synthetic Aperture Radars be used to Estimate Hurricane Force Winds? |
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| Autor(en): |
J. Horstmann, D.R. Thompson, F. Monaldo, H. C. Graber, and S. Iris |
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| Veröffentlicht in: |
Geophys. Res. Let., Vol. 32, L22801, DOI:10.1029/2005GL023992, 2005 |
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| Abstract: |
AWe compare wind fields retrieved from a RADARSAT-I synthetic aperture radar (SAR) image acquired over Hurricane Ivan on September 10, 2004 using the C-band geophysical model functions Cmod4 and its newest version Cmod5. Cmod4 has previously been shown to yield very good wind field estimates under low and moderate wind conditions. Wind directions obtained from streaks imaged by the SAR, that are well aligned with the mean surface wind direction are used to invert both algorithms to obtain estimates of the wind speed on scales of 1 km. These estimates are compared with predictions from a high resolution tropical cyclone model as well as local in situ data. It is found that the SAR wind speeds using Cmod5 agree reasonably well, while those from Cmod4 significantly under predict the measured wind speeds near the hurricane eye wall that reach values as high as 60 ms-1. |
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| Link: |
http://dx.doi.org/10.1029/2005GL023992 |
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| Titel: |
Relationship between SAR-Derived Wind Vectors and Wind at 10-m Height Represented by a Mesoscale Model |
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| Autor(en): |
Wolfgang Koch and Frauke Feser |
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| Veröffentlicht in: |
Monthly Weather Review, 134(5), p.1505-1517, 2006 |
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| Abstract: |
Wind vectors over the ocean were extracted from a large number of SAR images from the European satellites ERS-1 and ERS-2. The wind directions are inferred from the orientation of wind streaks that are imaged by the SAR, while the wind speeds are retrieved by inversion of the C-band model CMOD4. The derived wind directions and speeds were compared to wind vectors from the numerical model REMO that are available hourly on a 55 km grid. The large number of comparisons and independent weather situations allowed for an analysis of subsets, that are classified by SAR derived wind speed. A strong decrease of the standard deviation of directional differences with increasing wind speed was found. Biases of directional differences depend on SAR wind speed as well. Furthermore, the influence of the temporal difference between SAR over flight and model and an automatic image filtering on the directional error is demonstrated. Overall, reasonable fields of wind vectors were extracted from SAR imagery in seventy of eighty cases. These fields provide valuable information for validation of numerical models of the atmosphere and case studies of coastal wind fields. |
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| Link: |
http://dx.doi.org/10.1175/MWR3134.1 |
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| Titel: |
Unusual wave conditions in the Baltic Proper and in the Gulf of Finland during windstorm Gudrun |
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| Autor(en): |
T. Soomere, A. Behrens, L. Tuomi, and J. W. Nielsen |
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| Veröffentlicht in: |
Boreal Environment Research, submitted in 2005 |
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| Abstract: |
Wave conditions in the northern Baltic Proper during windstorm Erwin/Gudrun (January 2005) are analysed. The measured wave heights were modest (maximum significant wave height 7.2 m) only because the most rough seas occurred remote from the wave sensors. The operational wave models from the German Weather Forecast Service, the Danish Meteorological Institute and the Finnish Institute of Marine Research indicate that the largest waves occurred off the coasts of Saaremaa and Latvia where the significant wave heights most probably exceeded 10 m; however, reaching values close to 11 m was unlikely. These models well captured the basic features of wave conditions for 48--54 hours ahead, and accurately reproduced wave properties in forecasts for 24 - 36 hours. The dominating wave periods were about 12 s in a large part of the northern Baltic Proper. Exceptionally long waves with peak periods up to 12 s also occurred in the central part of the Gulf of Finland. |
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| Titel: |
Changing waves and storms in the Northeast Atlantic? |
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| Autor(en): |
The Wasa Group |
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| Veröffentlicht in: |
Bull. Amer. Met. Soc. 79, 741-760, 1998 |
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| Abstract: |
The European project WASA (Waves and Storms in the North Atlantic) has been set up to verify or disprove hypotheses of a worsening storm and wave climate in the northeast Atlantic and its adjacent seas in the present century. Its main conclusion is that the storm and wave climate in most of the northeast Atlantic and in the North Sea has undergone significant variations on timescales of decades; it has indeed roughened in recent decades, but the present intensity of the storm and wave climate seems to be comparable with that at the beginning of this century. Part of this variability is found to be related to the North Atlantic oscillation. An analysis of a high-resolution climate change experiment, mimicking global warming due to increased greenhouse gas concentrations, results in a weak increase of storm activity and (extreme) wave heights in the Bay of Biscay and in the North Sea, while storm action and waves slightly decrease along the Norwegian coast and in most of the remaining North Atlantic area. A weak increase in storm surges in the southern and eastern part of the North Sea is expected. These projected anthropogenic changes at the time of CO2 doubling fall well within the limits of variability observed in the past. A major methodical obstacle for the assessment of changes in the intensity of storm and wave events are inhomogeneities in the observational record, both in terms of local observations and of analyzed products (such as weather maps), which usually produce an artificial increase of extreme winds. This occurs because older analyses were based on fewer observations and with more limited conceptual and numerical models of the dynamical processes than more recent analyses. Therefore the assessment of changes in storminess is based on local observations of air pressure and high-frequency variance at tide gauges. Data of this sort is available for 100 yr and sometimes more. The assessment of changes in the wave climate is achieved using a two-step procedure; first a state-of-the-art wave model is integrated with 40 yr of wind analysis; the results are assumed to be reasonably homogeneous in the area south of 70°N and east of 20°W; then a regression is built that relates monthly mean air pressure distributions to intramonthly percentiles of wave heights at selected locations with the help of the 40-yr simulated data; finally, observed monthly mean air pressure fields from the beginning of this century are fed into the regression model to derive best guesses of wave statistics throughout the century. |
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| Link: |
http://w3g.gkss.de/G/Mitarbeiter/storch/pdf/wasa_1998.pdf |
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| Titel: |
Northeast Atlantic and North Sea storminess as simulated by a regional climate model 1958-2001 and comparison with observations |
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| Autor(en): |
Ralf Weisse, Hans von Storch, and Frauke Feser |
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| Veröffentlicht in: |
J. Climate, 18(3), 465-479, 2005 |
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| Abstract: |
An analysis of the storm climate of the Northeast Atlantic and the North Sea as simulated by a regional climate model for the past 44 years is presented. The model simulates the period 1958-2001 driven by the National Center for Environmental Prediction's (NCEP's) weather re-analysis. Comparison with observations shows that the model is capable of reproducing impact related storm indices such as the number of severe and moderate storms per year or the total number of storms and upper intra-annual percentiles of near-surface wind speed. The indices describe both, the year-to-year variability of the frequency as well as changes in the average intensity of storm events. Analysis of these indices reveals that the average number of storms per year has increased near the exit of the North Atlantic Storm track and over the Southern North Sea since the beginning of the simulation period (1958), but the increase has attenuated later over the North Sea and the average number of storms per year is decreasing over the Northeast Atlantic since about 1990-1995. The frequency of the most severe storms follows a similar pattern over the Northeast North Atlantic while there occurred too few severe storms in other areas of the model domain preventing a statistical analysis for these areas. |
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| Link: |
http://dx.doi.org/10.1175/JCLI-3281.1 |
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| Titel: |
Storm-related sea level variations along the North Sea coast as simulated by a high-resolution model 1958-2002 |
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| Autor(en): |
Ralf Weisse and Andreas Pluess |
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| Veröffentlicht in: |
Ocean Dynamics, 56(1), 16-25, 2006 (online 2005), doi:10.1007/s10236-005-0037-y |
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| Abstract: |
Storm-related sea level variations 1958-2002 along the North Sea coast from a high-resolution numerical hindcast are investigated and compared to the results of earlier studies. Considerable variations were found from year to year and over the entire period. The large scale pattern of these variations is consistent with that derived from previous studies while the magnitudes of the long-term trends differ. The latter is attributed to different analysis periods, improvements in the atmospheric forcing and the enhanced spatial resolution of the numerical simulation. It is shown that in particular the different analysis periods represent an issue as the increase in storm related sea levels was found to be weaker over the last few years that have not been included in earlier studies. These changes are consistent with observed changes of the storm climate over the North Sea. In addition it is shown, that observed and hindcast trends may differ significantly. While the latter are in agreement with observed changes in the storm climate it may be concluded that observed sea level changes along the North Sea coast comprise a considerable fraction that can not be attributed to changes in the large scale atmospheric circulation. |
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| Link: |
http://dx.doi.org/10.1007/s10236-005-0037-y |
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| Titel: |
North Sea storm surge statistics based on projections in a warmer climate: How important are the driving GCM and the chosen emission scenario? |
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| Autor(en): |
Katja Woth |
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| Veröffentlicht in: |
Geophys. Res. Lett., 32:L22708, doi:10.1029/2005GL023762, 2005 |
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| Abstract: |
Climate models, simulating the effect of plausible future emission concentrations (scenarios), describe for the future an increase of high wind speeds over Northwest Europe during winter. With the help of a hydrodynamic model of the North Sea, these atmospheric future conditions are used to project storm surge heights for the Northwest European Shelf Sea. Four different projections are presented, all generated with the same Regional Climate Model, which itself is driven with two different Global Climate Model scenarios both exposed to two different emission scenarios. The analyses are carried out for a 30-year time-slice at the end of the 21st century. All four ensemble members point to a significant increase of storm surge elevations for the continental North Sea coast of between 15 and almost 25 cm. However, the different storm surge projections are not statistically distinguishable from each other but can provide a range of possible evolutions of surge extremes in a warmer climate. |
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| Link: |
http://dx.doi.org/10.1029/2005GL023762 |
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| Titel: |
Climate change and North Sea storm surge extremes: An ensemble study of storm surge extremes expected in a changed climate projected by four different Regional Climate Models |
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| Autor(en): |
Katja Woth, Ralf Weisse, and Hans von Storch |
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| Veröffentlicht in: |
Ocean Dynamics, 56(1), 3-15, 2006 (2005 online), doi:10.1007/s10236-005-0024-3 |
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| Abstract: |
The Coastal Zones are facing the prospect of changing storm surge statistics due to anthropogenic climate change. In the present study we examine these prospects for the North Sea based on numerical modeling. The main tool is the barotropic tide-surge model TRIMGEO (Tidal Residual and Intertidal Mudflat Model) to derive storm surge climate and extremes from atmospheric conditions. The analysis is carried out by using an ensemble of four 30-year atmospheric regional simulations under present-day and possible future enhanced greenhouse gas conditions. The atmospheric regional simulations were prepared within the EU project PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects). The research strategy of PRUDENCE is to compare simulations of different regional models driven by the same global control and climate change simulations. These global conditions, representative for 1961-1990 and 2071-2100 were prepared by the Hadley Center based on the IPCC A2 SRES scenario. The results suggest that under future climate conditions storm surge extremes may increase along the North Sea coast towards the end of this century. Based on a comparison between the results of the different ensemble members as well as on the variability estimated from a high-resolution storm surge reconstruction of the recent decades it is found that this increase is significantly different from zero at the 95% confidence level for most of the North Sea coast. An exception represents the East coast of the UK which is not affected by this increase of storm surge extremes. |
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| Link: |
http://dx.doi.org/10.1007/s10236-005-0024-3 |
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