Evaluation of a COSMO-based reanalysis system for the European CORDEX domain Christian Ohlwein1,2, Jan Keller1,4, Christoph Bollmeyer1,2, Sabrina Bentzien1,2, Petra Friederichs2, Andreas Hense2, Susanne Crewell3, Ieda Pscheidt1,2, Stephanie Redl1,3, Sandra Steinke1,3 Hans-Ertel-Centre for Weather Research – Climate Monitoring Branch Meteorological Institute, University of Bonn 3 Institute for Geophysics and Meteorology, University Cologne 4 Deutscher Wetterdienst DWD 1 2 http://www.herz-tb4.uni-bonn.de Interna(onal Symposium on Data Assimila(on 2014, Munich, Germany, February 2014 Objective è Develop methods for monitoring regional climate for operational use at DWD Outline è Development of a regional reanalysis system § Set-up and characteristics § Status and perspectives è Evaluation § Various aspects of verification and validation Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Regional Reanalyses COSMO-REA2 COSMO-DE (2 km) 724 × 780 848 × 824 Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Regional Reanalysis System ERA-Interim Reanalysis (T255) COSMO-REA6 (6.2 km) § CORDEX EUR-11 domain § Data assimilation … Soil moisture analysis (SMA) Continuous nudging SYNOP, SHIP, PILOT, TEMP, AIREP, AMDAR, ACARS,… COSMO-REA2 (2.0 km) § COSMO-DE domain § Data assimilation … SST analysis (daily) Snow analysis (6-hourly) Latent heat nudging (LHN) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Regional Reanalysis System ERA-Interim Reanalysis (T255) COSMO-DS6 (6.2 km) § CORDEX EUR-11 domain § Downscaling only Soil moisture analysis (SMA) Continuous nudging SYNOP, SHIP, PILOT, TEMP, AIREP, AMDAR, ACARS,… SST analysis (daily) Snow analysis (6-hourly) Latent heat nudging (LHN) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Model Output è Direct Model Output § 150 fields (2D/3D) § 60 min (3D) and 15 min (2D) è Current status § COSMO-REA6: 2007–2012 § COSMO-REA2: 2011 è Next steps § Time-slots in the past § COSMO-REA6: 1979–1983, … Example: Precipitation simulated by COSMOREA6 (blue) and COSMO-DS6 (grey) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Outline è Development of a regional reanalysis system § Set-up and characteristics § Status and perspectives è Evaluation § Various aspects of verification and validation Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Distribution Integrated Quadratic Distance* (IQD) COSMO-CORDEX / German SYNOP stations (2011) *) cf. Thorarinsdottir et al. (2013): Using proper divergence functions to evaluate climate models Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Extremes 1.0 2.5 SYNOP COSMO−REA COSMO−DS ERA−INTERIM* 1.5 1.0 0.5 SYNOP COSMO−REA COSMO−DS ERA−INTERIM* 0.8 Occurences [x103] Occurences [x106] 2.0 0.0 (Sharpness) 0.6 0.4 0.2 <0.1 0.1−1.0 1.0−5.0 5.0−10.0 Precipitation [mm/3h] >10.0 0.0 20−30 30−40 40−50 50−60 Precipitation [mm/3h] >60 Histogram of 3-hourly precipitation events at German SYNOP stations (COSMO-REA6/DS6 simulations, 2011) *) note the change of support Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Frequency Bias (Bias) Frequency bias for 3-hourly precipitation events compared to German SYNOP stations (COSMO-REA6 simulations, 2011) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Log-Odds Ratio (Accuracy) Log-odds ratio for 3-hourly precipitation events compared to German SYNOP stations (COSMO-REA6 simulations, 2011) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Log-Odds Ratio (Accuracy) è Common attrib model perfo utes of rmance § Accuracy § Bias § Sharpness § Reli abilitystations Log-odds ratio for 3-hourly precipitation events compared to German SYNOP (COSMO-REA6 simulations, 2011) § … Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Model Output (REA6/REA2) Example: Precipitation simulated by COSMO-REA2 (blue) and COSMO-REA6 (grey) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Diurnal Cycle Mean precipitation intensities (>0.1 mm/h) at German SYNOP stations (June–August 2011) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Further Evaluation è Standard evaluation § Analysis increments § Water and energy cycle § … è Spatial verification § Object-based § … è Remote sensing data § AMSU-B Microwave Humidity Sensor § MSG brightness temperature § IWV from GNSS measurements § Ceilometer measurements § … Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch è Overa ll quality § More com ? plicated t han for interp olation approach es § Beyond s tandard s cores § Physical processe s § … Further Evaluation – Clouds Brightness temperature (10.8 µm) – COSMO-REA (LHN test runs at 2.8 km) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Further Evaluation – Frozen Hydrometeors AMSU-B COSMO-REA6 Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Outline è Development of a regional reanalysis system § Set-up and characteristics § Status and perspectives è Evaluation § Various aspects of verification and validation Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Summary è High-resolution regional reanalysis system § COSMO-REA6: CORDEX EUR-11 domain (6.2 km) § COSMO-REA2: COSMO-DE domain (2.0 km) è Evaluation of the system § Common attributes of model performance § Sharpness: representation of spatio-temporal variability § Accuracy: coherence between model and independent observations § … § Beyond standard scores: physical processes è Perspectives § UERRA: Uncertainties in ensembles of regional reanalysis (FP7-SPACE) Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Evaluation of a COSMO-based reanalysis system for the European CORDEX domain Christian Ohlwein1,2, Jan Keller1,4, Christoph Bollmeyer1,2, Sabrina Bentzien1,2, Petra Friederichs2, Andreas Hense2, Susanne Crewell3, Ieda Pscheidt1,2, Stephanie Redl1,3, Sandra Steinke1,3 Hans-Ertel-Centre for Weather Research – Climate Monitoring Branch Meteorological Institute, University of Bonn 3 Institute for Geophysics and Meteorology, University Cologne 4 Deutscher Wetterdienst DWD 1 2 http://www.herz-tb4.uni-bonn.de Interna(onal Symposium on Data Assimila(on 2014, Munich, Germany, February 2014 Outline è Appendix Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Assimilation of rain gauge measurements è Spatio-temporal disaggregation § Rain gauge measurements § Covariates such as MSG TB è Assimilation via LHN § Prerequisite for long-term runs of COSMO-REA2 3 August 2007, 02–03 UTC Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch Precipitation – Extremes * * Histogram of 3-hourly precipitation events at German SYNOP stations (June–August 2011) *) note the change of support Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch
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