TY - GEN A1 - Jacob, Daniela A1 - Keuler, Klaus A1 - Georgievski, Goran A1 - Radtke, Kai T1 - EURO-CORDEX: new high-resolution climate change projections for European impact research T2 - Regional Environmental Change N2 - A new high-resolution regional climate change ensemble has been established for Europe within the World Climate Research Program Coordinated Regional Downscaling Experiment (EURO-CORDEX) initiative. The first set of simulations with a horizontal resolution of 12.5 km was completed for the new emission scenarios RCP4.5 and RCP8.5 with more simulations expected to follow. The aim of this paper is to present this data set to the different communities active in regional climate modelling, impact assessment and adaptation. The EURO-CORDEX ensemble results have been compared to the SRES A1B simulation results achieved within the ENSEMBLES project. The large-scale patterns of changes in mean temperature and precipitation are similar in all three scenarios, but they differ in regional details, which can partly be related to the higher resolution in EURO-CORDEX. The results strengthen those obtained in ENSEMBLES, but need further investigations. The analysis of impact indices shows that for RCP8.5, there is a substantially larger change projected for temperature-based indices than for RCP4.5. The difference is less pronounced for precipitation-based indices. Two effects of the increased resolution can be regarded as an added value of regional climate simulations. Regional climate model simulations provide higher daily precipitation intensities, which are completely missing in the global climate model simulations, and they provide a significantly different climate change of daily precipitation intensities resulting in a smoother shift from weak to moderate and high intensities. Y1 - 2014 U6 - https://doi.org/10.1007/s10113-013-0499-2 SN - 1436-378X VL - 14 IS - 2 SP - 563 EP - 578 ER - TY - GEN A1 - Jacob, Daniela A1 - Keuler, Klaus A1 - Georgievski, Goran A1 - Radtke, Kai T1 - Erratum to: EURO-CORDEX: new high-resolution climate change projections for European impact research T2 - Regional Environmental Change Y1 - 2014 U6 - https://doi.org/10.1007/s10113-014-0587-y SN - 1436-378X N1 - weitere Autoren VL - 14 IS - 2 SP - 579 EP - 581 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 - 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 - 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 - GEN A1 - Casanueva, Anna A1 - Keuler, Klaus A1 - Kotlarski, Sven A1 - Herrera, Sixto A1 - Fernández, Jésus A1 - Gutiérrez, J. M. A1 - Boberg, Fredrik A1 - Colette, Augustin A1 - Bøssing Christensen, Ole A1 - Goergen, Klaus A1 - Jacob, Daniela A1 - Nikulin, Grigory A1 - Teichmann, Claas A1 - Vautard, Robert T1 - Daily precipitation statistics in a EURO-CORDEX RCM ensemble: Added value of raw and bias-corrected high-resolution simulations T2 - Climate Dynamics N2 - Daily precipitation statistics as simulated by the ERA-Interim-driven EURO-CORDEX regional climate model (RCM) ensemble are evaluated over two distinct regions of the European continent, namely the European Alps and Spain. The potential added value of the high-resolution 12 km experiments with respect to their 50 km resolution counterparts is investigated. The statistics considered consist of wet-day intensity and precipitation frequency as a measure of mean precipitation, and three precipitation-derived indicators (90th percentile on wet days—90pWET, contribution of the very wet days to total precipitation—R95pTOT and number of consecutive dry days—CDD). As reference for model evaluation high resolution gridded observational data over continental Spain (Spain011/044) and the Alpine region (EURO4M-APGD) are used. The assessment and comparison of the two resolutions is accomplished not only on their original horizontal grids (approximately 12 and 50 km), but the high-resolution RCMs are additionally regridded onto the coarse 50 km grid by grid cell aggregation for the direct comparison with the low resolution simulations. The direct application of RCMs e.g. in many impact modelling studies is hampered by model biases. Therefore bias correction (BC) techniques are needed at both resolutions to ensure a better agreement between models and observations. In this work, the added value of the high resolution (before and after the bias correction) is assessed and the suitability of these BC methods is also discussed. Three basic BC methods are applied to isolate the effect of biases in mean precipitation, wet-day intensity and wet-day frequency on the derived indicators. Daily precipitation percentiles are strongly affected by biases in the wet-day intensity, whereas the dry spells are better represented when the simulated precipitation frequency is adjusted to the observed one. This confirms that there is no single optimal way to correct for RCM biases, since correcting some distributional features typically leads to an improvement of some aspects but to a deterioration of others. Regarding mean seasonal biases before the BC, we find only limited evidence for an added value of the higher resolution in the precipitation intensity and frequency or in the derived indicators. Thereby, evaluation results considerably depend on the RCM, season and indicator considered. High resolution simulations better reproduce the indicators’ spatial patterns, especially in terms of spatial correlation. However, this improvement is not statistically significant after applying specific BC methods. KW - dded value; Bias correction; EURO-CORDEX; Precipitation indices; Regional climate models Y1 - 2016 U6 - https://doi.org/10.1007/s00382-015-2865-x SN - 1432-0894 VL - 47 IS - 3/4 SP - 719 EP - 737 ER - TY - GEN A1 - Kjellström, Erik A1 - Nikulin, Grigory A1 - Strandberg, Gustav A1 - Bøssing Christensen, Ole A1 - Jacob, Daniela A1 - Keuler, Klaus A1 - Lenderink, Geert A1 - Meijgaard, Erik van A1 - Schär, Christoph A1 - Somot, Samuel T1 - European climate change at global mean temperature increases of 1.5 and 2°C above pre-industrial conditions as simulated by the EURO-CORDEX regional climate models T2 - Earth System Dynamics Y1 - 2018 U6 - https://doi.org/10.5194/esd-9-459-2018 SN - 2190-4987 N1 - viele weitere Autoren IS - 9 SP - 459 EP - 478 ER - TY - RPRT A1 - Keuler, Klaus A1 - Block, Alexander A1 - Ahrens, Wilfried A1 - Jacob, Daniela A1 - Rechid, Diana A1 - Kotova, Lola A1 - Kotlarski, Sven A1 - Heimann, Dietrich A1 - Zemsch, Maria A1 - Knoche, Richard A1 - Dittmann, Ernst A1 - Walter, Andreas A1 - Berger, Franz A1 - Sommer, Michael T1 - QUIRCS: Quantification of uncertainties in regional climate and climate change simulations. German Climate Research Programme (2001-2006), Final Symposium 2005 N2 - The comparison of multi model runs of the reference period 1979-1993 with different observational data sets for several climate parameters enables the quantification of the model uncertainties in representing present-day climate conditions for Central Europe. The quantification is based on a number of objective distance measures which detect differences in the spatial and temporal structures of the data sets being compared. Additional climate change simulations of two 30-year periods (control and scenario simulation) are performed for the SRES B2 global change scenario. They indicate a severe warming for Germany with values of up to 4 K in summer which is much higher than the quantified uncertainty range of the regional models for this climate parameter. For precipitation in Germany, a weak reduction during the summer months is overcompensated by an increase in winter and fall. However, the simulated changes are smaller than the quantified uncertainty range for the regional models so that in particular a significant reduction of the annual precipitation in Germany cannot be stated on basis of the current simulations for the B2 scenario. Aim of the research in the context of DEKLIM A reliable assessment of possible future climate developments requires an improved understanding of climate and its variability as well as a detailed knowledge of the uncertainties of climate simulations which provide the requested information about the potential degree of future changes. The project QUIRCS focuses on the climate patterns of Central Europe and investigates the quality of currently used regional climate models and regionalization techniques by a model inter-comparison, a substantial model evaluation, additional sensitivity studies and an extensive analysis of climate data. The major scientific aims are • to quantify the uncertainties of regional climate simulations and of observed climate data, • to provide a regional climate change scenario for Europe with a particular focus on Germany, • to assess the reliability of the produced climate change signals with respect to the Collapse. KW - regional climate simulation KW - model evaluation KW - uncertainty KW - climate change KW - climate data Y1 - 2005 UR - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.596.557&rep=rep1&type=pdf PB - DLR CY - Bonn ER - TY - RPRT A1 - Keuler, Klaus A1 - Knoche, Hans-Richard A1 - Jacob, Daniela T1 - Möglichkeiten und Grenzen regionaler Klimamodelle T2 - Regionale Klimamodelle – Potentiale, Grenzen und Perspektiven Y1 - 2010 UR - https://www.dkn-future-earth.org/imperia/md/content/dkn/regionale_klimamodelle_low.pdf SN - 978-3-9813068-1-1 PB - Nationales Komitee für Global Change Forschung c/o Institut für Weltwirtschaft CY - Kiel ER - TY - RPRT A1 - Keuler, Klaus A1 - Block, Alexander A1 - Ahrens, Wilfried A1 - Jacob, Daniela A1 - Rechid, Diana A1 - Kotova, Lola A1 - Kotlarski, Sven A1 - Heimann, Dietrich A1 - Zemsch, Maria A1 - Knoche, Richard A1 - Dittmann, Ernst A1 - Walter, Andreas A1 - Berger, Franz A1 - Sommer, Michael T1 - Quantifizierung von Ungenauigkeiten regionaler Klima- und Klimaänderungssimulationen (QUIRCS). Zusammenfassung der wesentlichen Ergebnisse eines Projektes des deutschen Klimaforschungsprogramms DEKLIM N2 - Das Projekt QUIRCS (“Quantification of Uncertainties in Regional Climate and Climate-Change Simulations“) ist eines von insgesamt37Verbundforschungsprojekten, die im Rahmen des Deutschen Klimaforschungsprogramms DEKLIM vom BMBF als Beitrag zum Teilbereich „Klima-forschung und Vorhersagbarkeit“ gefördert worden sind [DEKLIM, 2005]. Unter der Koordination des Lehrstuhls Umweltmeteorologie der Brandenburgischen Technischen Universität (BTU) Cottbus waren 6 Institutionen mit insgesamt 13 Mitarbeitern über 4 Jahre an der Durchführung des Projektes beteiligt. Der vorliegende Bericht gibt einen Überblick über die verschiedenen Aufgabenstellungen und fasst die wesentlichen Ergebnisse des Projektes zusammen. Y1 - 2006 UR - https://www-docs.b-tu.de/fg-meteorologie/public/publikationen/quircs_abschlussbericht.pdf ER -