1. Heavy precipitation Heavy precipitation Poland under water, July 1997 Group 13 Convective closure shemesDomain size & resolution Soil moistureBoundary conditions T. Spektorman (Uzbekistan)E. Vanvyve (Belgium)M. Liszewska (Poland)

2. The flood of July 1997 in Poland Wroclaw 1 st flood peak 2 nd flood peak

3. What did we do ? RegCMBoundary conditions NCEPECMWF Small domain 40/60 km Large domain 60 km Fritsch & Chappell Arakawa & Schubert

4. PlanPlan  Results Sensitivity to convective closure schemes and boundary conditions Sensitivity to convective closure schemes and boundary conditions Sensitivity to soil moisture Sensitivity to soil moisture Sensitivity to domain size and resolution Sensitivity to domain size and resolution  Conclusion

5. CC shemes & BCs - P surface (monthly mean) Arakawa-SchubertFritsch-Chappell NCEP  ECMWF 

6. CC shemes & BCs – T 2m (monthly mean) Arakawa-SchubertFritsch-Chappell NCEP  ECMWF  CRU

7. CC shemes & BCs - precipitation (monthly rate) Arakawa-SchubertFritsch-Chappell NCEP  ECMWF  CRU

8. CC shemes & BCs - Precipitation (6h) Arakawa-SchubertFritsch-Chappell NCEP  ECMWF  Average on the flood area

9. PlanPlan  Results Sensitivity to convective closure schemes and boundary conditions Sensitivity to convective closure schemes and boundary conditions Sensitivity to soil moisture Sensitivity to soil moisture Sensitivity to domain size and resolution Sensitivity to domain size and resolution  Conclusion

10. How the soil moisture can influence the precipitation ? Initial soil moisture in and around the flood area set to 100%.  Precipitation for the 2 flood peaks Sensitivity to soil moisture

11. Sensitivity to the soil moisture 1 st flood peak (4-7 th July) 2 nd flood peak (18-20 th July) “normal” soil moisture  “modified” soil moisture  1 st flood peak 2 nd flood peak NCEP Fritsch & Chappell

12. PlanPlan  Results Sensitivity to convective closure schemes and boundary conditions Sensitivity to convective closure schemes and boundary conditions Sensitivity to soil moisture Sensitivity to soil moisture Sensitivity to the domain size and the resolution Sensitivity to the domain size and the resolution  Conclusion

13. Sensitivity to domain size and resolution “small” domain – 60 km“small” domain – 40 km total precipitation  convective precipitation  Average on the 3 days of the 2 nd flood peak “large” domain – 60 km NCEP Arakawa & Schubert

14. PlanPlan  Simulations setup  Results Sensitivity to Sensitivity to ­convective closure schemes ­boundary conditions Does the soil moisture matter for the peak flood ? Sensitivity to the domain size and the resolution Sensitivity to the domain size and the resolution  Conclusion

15. Preliminary conclusion  Sensitivity to forcing fields no difference for monthly mean T 2m and P surface no difference for monthly mean T 2m and P surface NCEP seems dryer than ECMWF NCEP seems dryer than ECMWF  Sensitivity to convective closure schemes no difference for monthly mean T 2m and P surface no difference for monthly mean T 2m and P surface regional precipitation pattern captured regional precipitation pattern captured flood peaks more or less corresponding to the real situation flood peaks more or less corresponding to the real situation  Sensitivity to soil moisture difficult to say, more investigation needed difficult to say, more investigation needed  Sensitivity to domain size and resolution more detailed convective precipitation pattern for higher resolution more detailed convective precipitation pattern for higher resolution

16. Thanks for your patience ! Last words … Our first conclusion was : “Still a lot of very hard work and white nights …” That was true !!

17. Sensitivity to CC schemes and BCs  Domain “small” domain (40*50*18) “small” domain (40*50*18) 60 km resolution 60 km resolution  Convective closure schemes Arakawa & Schubert Arakawa & Schubert Fritsch & Chappell Fritsch & Chappell  Boundary conditions NCEP NCEP ECMWF ECMWF  Monthly/daily pressure, temperature and precipitation