TY - GEN A1 - Panitz, Hans-Jürgen A1 - Dosio, Alessandro A1 - Büchner, Mathias A1 - Lüthi, Daniel A1 - Keuler, Klaus T1 - COSMO-CLM (CCLM) climate simulations over CORDEX Africa domain: Analysis of the ERA-Interim driven simulations at 0.44◦ and 0.22◦ resolution T2 - Climate Dynamics Y1 - 2014 U6 - https://doi.org/10.1007/s00382-013-1834-5 SN - 1432-0894 SN - 0930-7575 VL - 42 IS - 11-12 SP - 3015 EP - 3038 ER - TY - GEN A1 - Böhm, Uwe A1 - Keuler, Klaus A1 - Österle, Hermann A1 - Kücken, Martin A1 - Hauffe, Detlef T1 - Quality of a climate reconstruction for the CADSES regions T2 - Meteorologische Zeitschrift N2 - We used the regional climate model CCLM 4 to reconstruct the climate over the CADSES regions for the period 1961-2000. This most recent model version is currently still in a test phase. The simulation quality for this part of the entire simulation area is exemplarily analyzed by using a small but representative subset of model variables. Mean sea level pressure is chosen as an indicator for the behavior of the near-surface dynamics. Furthermore, the two regional variables 2 m temperature and precipitation are evaluated, which are of relevance for hydrological applications. For additional analyses to identify sources of uncertainty, we used soil moisture and cloudiness. Altogether, the accuracy of the simulation results can be judged as being in good agreement with the results of similar simulations by other regional climate models over Europe. Area-averaged monthly mean 2 m temperatures during winter show a cold bias of about -2 K. The simulated mean sea level pressure is with a bias of about 2 hPa slightly too high compared to the used reference data set. Although cloud cover evaluation hints at insufficiencies in the corresponding parameterization, further analyses are required to unambiguously identify the causes for this cold bias. During summer, higher 2 m temperatures linked to reduced precipitation are identified in nearly identical regions over southern and southeastern Europe. Further analyses of soil moisture evolution and cloud cover give evidence for a source of uncertainty in the surface hydrological scheme. Altogether, the detected differences do not exceed the typical ranges of uncertainty in comparable regional climate simulations over Europe. For input in hydrological applications, however, the uncertainties produced by the CCLM simulation described here have to be reduced in the medium term. N2 - Das Klima über den CADSES-Regionen wurde mit dem regionalen Klimamodell CCLM, Version 4.0 für den Zeitraum 1961-2000 rekonstruiert. Diese aktuellste Modellversion befindet sich gegenwärtig noch in einer Testphase. Die Qualität der Simulation für diesen Teil des Simulationsgebietes wird beispielhaft anhand einer kleinen, aber repräsentativen Teilmenge von Modellvariablen analysiert. Der Druck auf Meeresniveau wurde ausgewählt als Indikator für das Verhalten der bodennahen Dynamik. Weiterhin wurden die beiden Variablen 2 m Temperatur und Niederschlag als wichtige regionale Variablen für hydrologische Anwendungen bewertet. Für zusätzliche Analysen zur Identifizierung von Ungenauigkeitsquellen verwendeten wir die Bodenfeuchte und die Bewölkung. Insgesamt kann die Genauigkeit dieser Simulationsresultate als gut im Vergleich zu Ergebnissen von Simulationsläufen anderer regionaler Klimamodelle für Europa beurteilt werden. Gebietsmittel der monatlichen 2 m Temperaturen im Winter zeigen einen systematischen Fehler von etwa -2 K. Der simulierte Druck auf Meeresniveau ist mit einem systematischen Fehler von etwa 2 hPa etwas zu hoch im Vergleich zum verwendeten Referenzdatensatz. Obwohl die Evaluierung der Wolkendecke auf Unzulänglichkeiten in der entsprechenden Parametrisierung hinweist, sind weitere Analysen nötig, um die Ursachen für das systematisch zu kalte Modellverhalten eindeutig zu identifizieren. Im Sommer treten über nahezu identischen Regionen in Süd- und Südosteuropa höhere 2 m Temperaturen sowie geringere Niederschlägen auf. Weitere Analysen der zeitlichen Entwicklung der Bodenfeuchte und der Wolkenbedeckung geben Anhaltspunkte für eine Quelle von Ungenauigkeit im hydrologischen Teil des Bodenmodells. Insgesamt überschreiten die nachgewiesenen Unterschiede nicht die typischen Fehlerbereiche in vergleichbaren Klimasimulationen über Europa. Als Antrieb für hydrologische Anwendungen ist es allerdings mittelfristig erforderlich, die Ungenauigkeiten der hier beschriebenen CCLM-Simulation zu verringern. Y1 - 2008 U6 - https://doi.org/10.1127/0941-2948/2008/0318 SN - 1610-1227 VL - 17 IS - 4 SP - 477 EP - 485 ER - TY - GEN A1 - Feldmann, Hendrik A1 - Früh, Barbara A1 - Schädler, Gerd A1 - Panitz, Hans-Jürgen A1 - Keuler, Klaus A1 - Jacob, Daniela A1 - Lorenz, Peter T1 - Evaluation of the precipitation for south-western Germany from high resolution simulations with regional climate models T2 - Meteorologische Zeitschrift Y1 - 2008 U6 - https://doi.org/10.1127/0941-2948/2008/0295 SN - 1610-1227 VL - 17 IS - 4 SP - 455 EP - 465 ER - TY - GEN A1 - Walter, Andreas A1 - Keuler, Klaus A1 - Block, Alexander A1 - Knoche, Richard A1 - Block, Alexander A1 - Kotlarski, Sven A1 - Müller-Westermeier, Gerhard A1 - Rechid, Diana A1 - Ahrens, Wilfried T1 - A high resolution reference data set of german wind velocity 1951-2001 and comparison with regional climate model results T2 - Meteorologische Zeitschrift Y1 - 2006 U6 - https://doi.org/10.1127/0941-2948/2006/0162 SN - 1610-1227 VL - 15 IS - 6 SP - 585 EP - 596 ER - TY - GEN A1 - Böhm, Uwe A1 - Kücken, Martin A1 - Ahrens, Wilfried A1 - Block, Alexander A1 - Hauffe, Detlef A1 - Keuler, Klaus A1 - Rockel, Burkhardt A1 - Will, Andreas T1 - The Climate Version of LM: Brief Description and Long-Term Applications T2 - COSMO Newsletter Y1 - 2006 UR - http://www.cosmo-model.org/content/model/documentation/newsLetters/newsLetter06/newsLetter_06.pdf IS - 6 SP - 225 EP - 235 ER - TY - GEN A1 - Kotlarski, Sven A1 - Block, Alexander A1 - Böhm, Ursula A1 - Jacob, Daniela A1 - Keuler, Klaus A1 - Knoche, Richard A1 - Rechid, Diana A1 - Walter, Artur T1 - Regional Climate Model Simulations as Input for Hydrological Applications: Evaluation of Uncertainties T2 - Advances in Geoscience Y1 - 2005 U6 - https://doi.org/10.5194/adgeo-5-119-2005 IS - 5 SP - 119 EP - 125 ER - TY - GEN A1 - Vautard, Robert A1 - Gobiet, Andreas A1 - Keuler, Klaus T1 - The simulation of European heat waves from an ensemble of regional climate models within the EURO-CORDEX project T2 - Climate Dynamics Y1 - 2013 U6 - https://doi.org/10.1007/s00382-013-1714-z SN - 1432-0894 SN - 0930-7575 N1 - weitere Autoren VL - 41 IS - 9-10 SP - 2555 EP - 2575 ER - TY - GEN A1 - Georgievski, Goran A1 - Keuler, Klaus A1 - Will, Andreas A1 - Radtke, Kai T1 - Evaluation of Central European and Eastern Alpine seasonal climate simulated with CCLM: double nesting vs. direct forcing techniques T2 - COSMO Newsletter Y1 - 2011 UR - www.cosmo-model.org/content/model/documentation/newsLetters/newsLetter11/newsLetter_11.pdf IS - 11 SP - 133 EP - 142 ER - TY - GEN A1 - Früh, Barbara A1 - Feldmann, Hendrik A1 - Panitz, Hans-Jürgen A1 - Schädler, Gerd A1 - Jacob, Daniela A1 - Lorenz, Peter A1 - Keuler, Klaus T1 - Determination of precipitation return values in complex terrain and their evaluation T2 - Journal of Climate Y1 - 2010 U6 - https://doi.org/10.1175/2009JCLI2685.1 SN - 1520-0442 VL - 23 IS - 9 SP - 2257 EP - 2274 ER - TY - CHAP A1 - Keuler, Klaus A1 - Block, Alexander ED - Bärring, Lars ED - Laprise, Rene T1 - High resolution climate change simulation for Central Europe T2 - Extended abstracts of a WMO/WCRP-sponsored Regional-Scale Climate Modelling Workshop, high-resolution climate modelling, assessment, added value and applications, Lund, Sweden, 29 March-2 April 2004 Y1 - 2005 SP - 106 EP - 107 PB - Lund University CY - Lund, Sweden ER - TY - CHAP A1 - Keuler, Klaus A1 - Block, Alexander A1 - Schaller, Eberhard ED - Bärring, Lars ED - Laprise, Rene T1 - Assessment of quality and uncertainty in regional climate simulations T2 - Extended abstracts of a WMO/WCRP-sponsored Regional-Scale Climate Modelling Workshop, high-resolution climate modelling, assessment, added value and applications, Lund, Sweden, 29 March-2 April 2004 Y1 - 2005 SP - 68 EP - 69 PB - Lund University CY - Lund, Sweden ER - TY - CHAP A1 - Radtke, Kai S. A1 - Keuler, Klaus ED - Rockel, Burkhardt ED - Bärring, Lars ED - Reckermann, Marcus T1 - Climate change in Europe simulated by the regional climate model COSMO-CLM T2 - 2nd International Lund RCM Workshop : 21st Century Challenges in Regional-scale Climate Modelling, Lund University, Sweden, 4-8 May 2008, workshop proceedings Y1 - 2009 SP - 56 EP - 57 PB - International BALTEX Secretariat CY - GKSS Forschungszentrum Geesthacht ER - TY - CHAP A1 - Keuler, Klaus A1 - Radtke, Kai S. A1 - Schaller, Eberhard ED - Rockel, Burkhardt ED - Bärring, Lars ED - Reckermann, Marcus T1 - Effect of internal variability on regional climate change projections T2 - 2nd International Lund RCM Workshop : 21st Century Challenges in Regional-scale Climate Modelling, Lund University, Sweden, 4-8 May 2008, workshop proceedings Y1 - 2009 SP - 132 EP - 133 PB - International BALTEX Secretariat CY - GKSS Forschungszentrum Geesthacht ER - TY - GEN A1 - Mohr, Susanna A1 - Kunz, Michael A1 - Keuler, Klaus T1 - Development and application of a logistic model to estimate the past and future hail potential in Germany T2 - Journal of Geophysical Research: Atmospheres N2 - This study investigates to what extent the frequency of hail events in the summer months has changed during the past decades and which changes are expected to occur in the future. To improve the diagnostics of hail events by considering various factors relevant for the formation of hail, a logistic hail model has been developed by means of a multivariate analysis method. This statistical model is based on a combination of appropriate meteorological parameters (convective parameter, moisture content, etc.) and synoptic weather types. The output of the model is a new index that estimates the potential of the atmosphere for hailstorm development, referred to as potential hail index. Validations with independent data sets confirm the reliability of the model results. For Germany, the logistic hail model applied to reanalysis data over the past decades shows a markedly north‐to‐south gradient with most of the potential hail days occurring in the south. Applied to an ensemble of seven regional climate model simulations, it is found that the potential for hail events will increase in the future (2021–2050) compared to the past (1971–2000), but only statistically significant in the northwest and south of Germany. Y1 - 2015 U6 - https://doi.org/10.1002/2014JD022959 SN - 2169-8996 VL - 120 IS - 9 SP - 3939 EP - 3956 ER - TY - CHAP A1 - Brück, Yasemine A1 - Pohle, Ina A1 - Keuler, Klaus A1 - Schaller, Eberhard A1 - Hinz, Christoph T1 - Do mining lakes in the Lusatian Lignite mining region (Eastern Germany) affect regional precipitation patterns? T2 - European Geosciences Union, General Assembly 2016, Vienna, Austria N2 - Due to the flooding of former open-pit mines, Europe’s largest artificial lake district is created in Eastern Germany. Between 1990 and 2006 more than 80 km² of new lakes have already been formed. These large-scale land cover changes may impact regional meteorological characteristics, therefore it is of interest, whether effects of the mining lakes can already be observed. We especially focus on whether the evaporation from the mining pit lakes leads to a higher precipitation on their lee side. To detect changes in the precipitation patterns, we analysed daily precipitation data (1980-2014) of 25 stations in an area of 10 000 km² widely around the lake district. Under the assumption that the influences of the lakes should be detectable either directly as trends in the observed data or as a deviation from a general measure for precipitation we combined statistical tests and principal component analysis (PCA). We applied pre-whitening Mann-Kendall tests to detect precipitation trends and Mann-Whitney tests to detect differences between split samples (before and after the flooding of most of the lakes). The PCA was applied based on the correlation matrix of daily precipitation at the different stations. As the daily precipitation can sufficiently be explained by the first five principal components, the recombination of these five principal components was used as a general measure of precipitation in the region. By regression trees (random forests) a relation between the eigenvectors of the first five principal components and physiogeographic characteristics of the stations (e.g. altitude) was shown. Both the observed data and the deviations between the measurements and the recombination of the first five principal components showed divergent trends with high spatial variability and also interannual variability, but a pattern consistent with the lee side of the lake could not be detected. Therefore, it has been demonstrated that the emerging lakes had no influence on the daily precipitation at the stations considered in this study. This may be explained by the coarse spatial and also temporal resolution of precipitation measurements. Still, the approach presented here can be applied to (i) detect changes in the spatial pattern of climate variables by a combination of statistical tests and PCA and (ii) to analyse the relationships between such changes and physiogeographic characteristics by regression trees. Y1 - 2016 UR - http://meetingorganizer.copernicus.org/EGU2016/EGU2016-7663.pdf N1 - EGU2016-7663 PB - European Geophysical Society CY - Katlenburg-Lindau ER -