COSMO-SREPS Priority Project C. Marsigli ARPA-SIM - HydroMeteorological Service of Emilia-Romagna, Bologna, Italy

limited-area model error: schemes, parameters, surface forcings COSMO-SREPS methodology  i.c. and b.c. perturbations -> INM multi-model multi- boundary (SREPS)  model perturbations -> parameter perturbation (fixed value throughout the integration to test the impact of the different parameter perturbations) LAM ensemble driving model error analysis error at the global model scale larger scale errors smaller scale errors

System applications  COSMO Priority Project -> Short-Range Ensemble  1D-Var DA of satellite data to provide retrievals to be nudged within 7km COSMO-I7: test of the use of COSMO-SREPS to estimate a flow-dependent B matrix  COSMO-SREPS provides boundary conditions for the ensemble system at 2.8 km under development at DWD (COSMO-DE-EPS)

Involved COSMO people  Marsigli, Montani, Paccagnella (ARPA-SIM): 1.5 FTE  Flora Gofa, Petroula Louka (HNMS): verification, 0.5 FTE Collaboration:  Susanne Theis, Christoph Gebhardt (DWD): EELMK  Uli Schaettler (DWD): COSMO model code

Task 0. Preliminary actions for the system set-up: completed. Task 1. Definition of the methodologies to perturb model trajectories: completed Task 2. Definition of the methodologies to perturb initial conditions: suspended Task 3. System set-up: completed (set-up for the JJASON 2007 period during the MAP D-PHASE DOP) Task 4. Test on case studies: on-going (21 runs in autumn 2006 done, analysis on-going) Task 5. Test on a regular basis: on-going (running on the JJASON 2007 period during the MAP D-PHASE DOP) Task 6. Verification: on-going

System set-up 16 COSMO runs 10 km hor. res. 40 vertical levels COSMO at 25 km on IFS IFS – ECMWF global by INM Spain COSMO at 25 km on GME GME – DWD global COSMO at 25 km on UM UM – UKMO global COSMO at 25 km on NCEP AVN – NCEP global P1: control (ope) P2: conv. scheme (KF) P3: tur_len=1000 P4: pat_len=10000

intra-group distance 14 days (00UTC runs) 2mT whole domain

Daily precipitation ROC area Northern Italy + Switzerland observations Average over 0.5 x 0.5 deg boxes - +42h fc range

Daily precipitation ROC area Northern Italy + Switzerland observations Average over 0.5 x 0.5 deg boxes - +66h fc range

Relationship between error and spread 12UTC runs Northern Italy observations Nearest grid point

ensemble mean 2m Temperature nearest grid point

Ensemble member verification Precipitation – mm / 6h IFS GME UKMO NCEP

Ensemble member verification Precipitation – mm / 6h Tiedtke, pat_len500 Kain-Fritsch, pat_len500 Tiedtke, tur_len1000, pat_len500 Tiedtke, pat_len10000

Deterministic scores – ave 0.5 x 0.5 IT+SV 1mm/24h5mm/24h10mm/24h 12 UTC

Deterministic scores – ave 0.5 x 0.5 IT+SV 1mm/24h5mm/24h10mm/24h 12 UTC

Conclusions  ic and bc perturbations contribute to the spread for an amount approximately double with respect to the parameter perturbations, statistically over the whole domain and the whole period in terms of 2mT. Locally (in space and time) the situation can be quite different  the selected parameters produce a detectable spread among members with the same father  rms error is grater than spread for all the events but the correlation is good  different fathers contribute differently to the skill, for different parameters this is less clear

On-going activities  run of COSMO-SREPS with model perturbations for the DOP MAP D-PHASE (6 months, June-November 2007) :  statistical analysis of the system  comparison with the other available mesoscale ensemble systems  verification - system analysis (HNMS)  provide b.c. for DWD ensemble tests  test a flow-dependent B-matrix for 1D-Var of satellite data  test of different parameters (16 runs using only the IFS initial and boundary conditions)

Test of parameter perturbations (same father) 16 LM runs at 10 km P1: control (ope) P2: conv. scheme (KF) P3: parameter 1 P4: parameter 2 P5: … IFS – ECMWF global

Fine