COSMO-SREPS Priority Project

C. Marsigli

ARPA-SIM, Bologna, Italy

model (LM): schemes, parameters,

surface forcings

COSMO-SREPS

i.c. and b.c. perturbations -> INM multi-model

LM perturbations

aim: to develop a limited-area ensemble system for the short-range considering also small scale uncertainty

LAM ensemble

boundary conditions

initial conditions

people involved in the PP

Involved COSMO people:

• Marsigli, Montani, Paccagnella (ARPA-SIM)

+ collaborations:

• S. Theis (DWD) – discussion on the methodologies and sharing of perturbation techniques

• U. Schaettler (DWD) – new version of LM developed to move from the code to a namelist a number of tuneable parameters

• WG2 and WG3 people has provided a parameter list

Non-COSMO:

• INM (Spain): J. Garcia-Moya, J. Simarro, …

Task Suggested scientists(optional)

% FTE per year

start milestones date

0: Preliminary actions for the system set-up

people external to the project

0 September 2005 - LM code to LM by December 2005- INM initial and boundary conditions at ECMWF by June 2006

June 2006

1: Definition of the methodologies to perturb model trajectories

external collaboration of S. Theis

30% January 2006 - model parameters to be perturbed by December 2006

December 2006

2: Definition of the methodologies to perturb initial condition

   40%  October 2006  - ETKF implemented by the end of 2007

 June 2008

3: System set-up  external collaborations of INM and U. Schaettler

 5%  May 2006 - data transfer by INM for the first tests- 1-month test set-up by October 2006 - set-up of e-suite in 2007

June 2007

4: Test on case studies

  50% June 2006 - analysis of the impact of the different perturbations

December 2006

5: Test on a regular basis

   40%  January 2007   December 2007

6: Verification    20%  January 2007   October 2008

ic and bc: multi-model approach a MUlti-Model MUlti-Boundaries ensemble is operational at INM (Spain): 4 different limited-area models (HIRLAM, HRM, MM5, UM) are nested on 5 different global models (IFS, GME, AVN, UM, LM) => 20 members ensemble (25 km horizontal resolution)

LM has been added in May 2006

IFS LM 25km

GME LM 25km

AVN LM 25 km

Courtesy of INM

UM LM 25 km

COSMO-SREPS (Short-Range Ensemble

Prediction System) short range (up to 3 days)

16 LM runs at 10 km

LM at 25 km on IFS

IFS – ECMWF globalb

y I

NM

Sp

ain LM at 25 km on GME

GME – DWD global

LM at 25 km on UM

UM – UKMO global

LM at 25 km on NCEP

AVN – NCEP global

P1: conv. scheme (KF)

P2: turb. parameter 1

P3: time filter

P4: turb. parameter 2

Parameter listparameter name parameter description range default value usedPHYSICS

crsminminimal stomata resistance (part of 'terra'; sensible for much vegetation and not too dry soil [50,200] s/m 150 50, 200

c_soilsurface area index of the evaporating soil (part of 'terra'; sensible for less vegetation and not too dry soil ]0,c:lnd[ 0, clnd (=2)

plcovplant cover (part of 'terra' and 'turbtran'; controls transpiration) [0,1]

laileave area index (part of 'terra' and 'turbtran', controls transpiration) [0,10]

rlam_heat scaling factor of the laminar layer depth [0.1,50] 0.1, 50

c_difffactor for turbulent diffusion of TKE (may influence mixing at an inversion top) [0,2] 1 0, 2

pat_lenlength scale of thermal surface patterns (influences mixing in the stable stratified atmosphere) [0,10000] m 500 0, 10000

tur_lenmaximal turbulent length scale (influences mainly stratospheric mixing) [100,1000] m 1000

rat_canscaling parameter for the diagnosed canopy height (rather big influence on Td2m, but will be obsolete shortly) [0,10]

z0m_diaroughness length at a synop station (rather big influence on V10m, will very likely be obsolete in future) [0.05,0.5] m

NUMERICSl2tls 2-time-level scheme T or F false trueepsass Asselin filter coefficient [0.05,0.2] 0.15 0.05

13 15 UTC

47N

44N

6W 9W

13 18 UTC

47N

45N

7W

10W

14 00 UTC

46.5N

45N

10.5W 13W

14 06 UTC

13 May 12-18 UTC

COSMO-SREPS PROB. MAPS fc. range 12-18 18-24 24-30 h

COSMO-LEPS PROB. MAPS fc. range 0-6 6-12 12-18 h

> 10mm/6h

> 10mm/6h

10

30

60

90

100

COSMO-SREPS fc. range 24-30

14 May 0-6 UTC

ecmwf

gme

avn

ukmo

ensemble spread

12/05

12UTC

13/05

00UTC

13/05

12UTC

member behaviour (“father”)

intra-group distance

Task 0. Preliminary actions for the system set-up

Formal agreement between COSMO and INM:

• use of LM by INM: support has been given to INM -> done

• provision of the forecasts to COSMO: SREPS output available

From May 2006 3-hourly initial and boundary conditions for COSMO-SREPS are provided daily at ECMWF on ECFS: 4 LM runs at 25 km on an Euro-Atlantic area, nested on 4 different global models (IFS,GME,AVN,UKMO) interpolated with int2lm at 10 km over the COSMO-LEPS area

Task 1. Definition of the methodologies to perturb model trajectories

• Schemes (physics and numerics): Some schemes have been selected to be perturbed: Tiedtke, Tiedtke with cape closure, Kain-Fritsch, 2-time-level, Runge-Kutta

• Parameters:

• a first selection of the parameters has been done (analysis of few case studies)

• the new tuneable parameters will be tested (provided by external collaborations of WG3 people + Susanne Theis)

• Surface forcings: LM surface fields -> interest of Luca Bonaventura to test a technique for the perturbation of surface parameters -> to be developed

Task 2. Definition of the methodologies to perturb initial conditions: it will start in October with a visit to Bologna of Neill Bowler from UKMO.

Task 3. System set-up:• Data transfer between INM and ECMWF: done

• Adaptation of source code to give the possibility to use tuneable or random parameters: the new model version model will include a new namelist file in which many physical parameters can be set (Uli Schaettler, WG6) -> done

• Extracting LM frames and nesting of LM on LM frames (WG6): to be discussed

• Discussion on computer resources: during 2006 SP SPITLAEF is being used. A new Special Project submitted to ECMWF for the developing phase for 2007 (SPITFEAR). Collection of COSMO units to be discussed.

• Establish the link SIR-COSMO SREPS: this meeting

• Possibility to have a COSMO originating centre in the GRIB coding: to be discussed (possible link with TIGGE)

Task 4. Test on case studies

Test of SREPS prototype on real-time case studies and comparison with COSMO-LEPS and “model perturbed COSMO-LEPS”:

• run of COSMO-SREPS for 1 case study to test that the chain from INM to COSMO-SREPS is working -> done

• run of COSMO-SREPS with model perturbations only for 1 month of Autumn 2006:

• statistical analysis of the system

• provide b.c. for EELMK tests

• comparison with COSMO-LEPS and PEPS

Plans for 2006-2007Task 5. Test on a regular basis

• Task 5.1 selection of the methodology to generate the perturbations :

• parameters: based on the analysis of the results of the 1-month test period

• development of the i.c. perturbations technique

• Task 5.2 selection of the testing period:

• possible link with MAP D-PHASE (summer-autumn 2007)

• availability of observations (-> WG5)

• Task 5.3 investigation on computer resources:

• COSMO units available?

• Task 5.4 INM data availability

Plans for 2006-2008

Task 6. Verification

• Task 6.1 selection of the verification methodologies (with WG5)

• Task 6.2 selection of the reference data-set: COSMO observations, VERA analyses (MAP D-PHASE),…

• Task 6.3 computation of the score: comparison with COSMO-LEPS (and/or perturbed COSMO-LEPS?) and PEPS 

+ EELMK and SIR links