@misc{JacobKeulerGeorgievskietal., author = {Jacob, Daniela and Keuler, Klaus and Georgievski, Goran and Radtke, Kai}, title = {EURO-CORDEX: new high-resolution climate change projections for European impact research}, series = {Regional Environmental Change}, volume = {14}, journal = {Regional Environmental Change}, number = {2}, issn = {1436-378X}, doi = {10.1007/s10113-013-0499-2}, pages = {563 -- 578}, abstract = {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.}, language = {en} } @misc{JacobKeulerGeorgievskietal., author = {Jacob, Daniela and Keuler, Klaus and Georgievski, Goran and Radtke, Kai}, title = {Erratum to: EURO-CORDEX: new high-resolution climate change projections for European impact research}, series = {Regional Environmental Change}, volume = {14}, journal = {Regional Environmental Change}, number = {2}, issn = {1436-378X}, doi = {10.1007/s10113-014-0587-y}, pages = {579 -- 581}, language = {en} } @misc{FeldmannFruehSchaedleretal., author = {Feldmann, Hendrik and Fr{\"u}h, Barbara and Sch{\"a}dler, Gerd and Panitz, Hans-J{\"u}rgen and Keuler, Klaus and Jacob, Daniela and Lorenz, Peter}, title = {Evaluation of the precipitation for south-western Germany from high resolution simulations with regional climate models}, series = {Meteorologische Zeitschrift}, volume = {17}, journal = {Meteorologische Zeitschrift}, number = {4}, issn = {1610-1227}, doi = {10.1127/0941-2948/2008/0295}, pages = {455 -- 465}, language = {en} } @misc{KotlarskiBlockBoehmetal., author = {Kotlarski, Sven and Block, Alexander and B{\"o}hm, Ursula and Jacob, Daniela and Keuler, Klaus and Knoche, Richard and Rechid, Diana and Walter, Artur}, title = {Regional Climate Model Simulations as Input for Hydrological Applications: Evaluation of Uncertainties}, series = {Advances in Geoscience}, journal = {Advances in Geoscience}, number = {5}, doi = {10.5194/adgeo-5-119-2005}, pages = {119 -- 125}, language = {en} } @misc{FruehFeldmannPanitzetal., author = {Fr{\"u}h, Barbara and Feldmann, Hendrik and Panitz, Hans-J{\"u}rgen and Sch{\"a}dler, Gerd and Jacob, Daniela and Lorenz, Peter and Keuler, Klaus}, title = {Determination of precipitation return values in complex terrain and their evaluation}, series = {Journal of Climate}, volume = {23}, journal = {Journal of Climate}, number = {9}, issn = {1520-0442}, doi = {10.1175/2009JCLI2685.1}, pages = {2257 -- 2274}, language = {en} } @misc{CasanuevaKeulerKotlarskietal., author = {Casanueva, Anna and Keuler, Klaus and Kotlarski, Sven and Herrera, Sixto and Fern{\´a}ndez, J{\´e}sus and Guti{\´e}rrez, J. M. and Boberg, Fredrik and Colette, Augustin and B{\o}ssing Christensen, Ole and Goergen, Klaus and Jacob, Daniela and Nikulin, Grigory and Teichmann, Claas and Vautard, Robert}, title = {Daily precipitation statistics in a EURO-CORDEX RCM ensemble: Added value of raw and bias-corrected high-resolution simulations}, series = {Climate Dynamics}, volume = {47}, journal = {Climate Dynamics}, number = {3/4}, issn = {1432-0894}, doi = {10.1007/s00382-015-2865-x}, pages = {719 -- 737}, abstract = {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.}, language = {en} } @misc{KjellstroemNikulinStrandbergetal., author = {Kjellstr{\"o}m, Erik and Nikulin, Grigory and Strandberg, Gustav and B{\o}ssing Christensen, Ole and Jacob, Daniela and Keuler, Klaus and Lenderink, Geert and Meijgaard, Erik van and Sch{\"a}r, Christoph and Somot, Samuel}, title = {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}, series = {Earth System Dynamics}, journal = {Earth System Dynamics}, number = {9}, issn = {2190-4987}, doi = {10.5194/esd-9-459-2018}, pages = {459 -- 478}, language = {en} } @techreport{KeulerBlockAhrensetal., author = {Keuler, Klaus and Block, Alexander and Ahrens, Wilfried and Jacob, Daniela and Rechid, Diana and Kotova, Lola and Kotlarski, Sven and Heimann, Dietrich and Zemsch, Maria and Knoche, Richard and Dittmann, Ernst and Walter, Andreas and Berger, Franz and Sommer, Michael}, title = {QUIRCS: Quantification of uncertainties in regional climate and climate change simulations. German Climate Research Programme (2001-2006), Final Symposium 2005}, publisher = {DLR}, address = {Bonn}, pages = {9}, abstract = {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.}, language = {en} } @techreport{KeulerKnocheJacob, author = {Keuler, Klaus and Knoche, Hans-Richard and Jacob, Daniela}, title = {M{\"o}glichkeiten und Grenzen regionaler Klimamodelle}, series = {Regionale Klimamodelle - Potentiale, Grenzen und Perspektiven}, journal = {Regionale Klimamodelle - Potentiale, Grenzen und Perspektiven}, publisher = {Nationales Komitee f{\"u}r Global Change Forschung c/o Institut f{\"u}r Weltwirtschaft}, address = {Kiel}, isbn = {978-3-9813068-1-1}, pages = {2}, language = {de} } @techreport{KeulerBlockAhrensetal., author = {Keuler, Klaus and Block, Alexander and Ahrens, Wilfried and Jacob, Daniela and Rechid, Diana and Kotova, Lola and Kotlarski, Sven and Heimann, Dietrich and Zemsch, Maria and Knoche, Richard and Dittmann, Ernst and Walter, Andreas and Berger, Franz and Sommer, Michael}, title = {Quantifizierung von Ungenauigkeiten regionaler Klima- und Klima{\"a}nderungssimulationen (QUIRCS). Zusammenfassung der wesentlichen Ergebnisse eines Projektes des deutschen Klimaforschungsprogramms DEKLIM}, pages = {153}, abstract = {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" gef{\"o}rdert worden sind [DEKLIM, 2005]. Unter der Koordination des Lehrstuhls Umweltmeteorologie der Brandenburgischen Technischen Universit{\"a}t (BTU) Cottbus waren 6 Institutionen mit insgesamt 13 Mitarbeitern {\"u}ber 4 Jahre an der Durchf{\"u}hrung des Projektes beteiligt. Der vorliegende Bericht gibt einen {\"U}berblick {\"u}ber die verschiedenen Aufgabenstellungen und fasst die wesentlichen Ergebnisse des Projektes zusammen.}, language = {de} }