1. Testing bulk parameterization of microphysics in ALARO 10
Tomislav Kovacic
DHMZ, Croatia

2. ALARO 10 ALADIN dynamics + MNH physics
Hydrostatic version of AROME + parameterization of convection
Prototype
Leader: Gwenaelle Hello

3. Gard case Date: 2002-09-08 start time 2002-09-09 12
validity time=
Domain: A specific domain for this case 192x192 (smaller than aladin oper)

5. GARD TSTEP=30 s

6. GARD TSTEP=120 s

7. GARD TSTEP=360 s

8. Time splitting for microphysical scheme
Time step used in operational version of the model is to long for microphysics and the consequence is to few precipitation.
Time splitting for microphysical scheme has to be introduced in the model.
Iterations of microphysics:
microphysical scheme is performed several times in one time step of the model

9. Method Maximal amount of precipitation on the ground
Time steps: 30, 60, 120, 180, 240, 300, 360 and 400 s
Iterations: 1,2,3,6 and 9

10. GARD TIME=12 h

11. GARD TIME=12 h

12. GARD TIME=12 h

13. GARD TIME=12 h

14. GARD TIME=12 h

15. GARD TIME=12 h

16. GARD TIME=12 h

17. GARD TIME=12 h

18. GARD TIME=12 h

19. An other consequence
Geographical position of the precipitation area is changing
It moves upstream

20. GARD 9-8-2002 TSTEP=120 s ITERATIONS=1

21. GARD 9-8-2002 TSTEP=120 s ITERATIONS=3

22. GARD 9-8-2002 TSTEP=120 s ITERATIONS=3

23. Conclusions
The amount of precipitation increases with decreasing time step
It is converging for all studied cases
Time splitting doesn’t converge always and when it does it is not the same value as for the same time step of the model
Shorter time step must be used