1. Pre-operational testing of Aladin physics Martina Tudor 1, Ivana Stiperski 1, Vlasta Tutiš 1, Dunja Drvar 1 and Filip Vana 2 1 Meteorological and Hydrological Service, Grič 3, Zagreb, Croatia 2 Czech Hydrometeorological Institute, Na Šabatce 16, Prague, Czech Republic

2. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting2 Outline Methods –orography and GWD parameterization –radiation and cloudiness –horizontal diffusion Case studies Summary

3. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting3 Orography and GWD envelope has been removed from orography modified GWD introduced lift tested on a set of bura cases

4. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting4 Envelope vs. mean orography model orography with envelope (left), mean orography (center) and their difference (right)

5. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting5 14th November 2004, 10m wind 42 hour forecast in the oper (left) and experimental (centre) model version, and their difference (right), for the 8km (top) and 2km resolution (bottom)

6. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting6 New GWD scheme and new orography old GWD+envelope orography (left),old GWD+mean orography, new GWD+mean orography what has stronger influence on the prognosed wind field: new GWD scheme or new orography?

7. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting7 Comparison to measurements 10m wind forecast is compared to the 10m wind measurements giving good (left), bad (center) and ambiguous (right) results

8. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting8 Summary of the results Removal of the envelope and changes in gravity wave drag parametrization result in : –stronger winds on the windward and generally weaker winds on the leeward side of the obstacle, as expected –Mountain wave amplitude is reduced and smoothed –Sub-grid scale orography representation has bigger impact on the results than modified gravity wave parametrization

9. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting9 Radiation and cloudiness Random, random maximum and maximum cloud overlap assumptions, Different critical relative humidity profiles (“old” and “new”) Cloudiness schemes: –Operational –Xu-Randall (1996) Radiation schemes: –Operational –Operational including net exchange rate formulation (NER) –FMR scheme (Morcrette, 1989) called with different intervals.

10. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting10 The fog case Meteosat-8 RBG composite of channels 3.9, 10.8 and 12.0 µm for December 15th 2004, 06 UTC. Fog or low clouds over Southeastern Europe are clearly visible.

11. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting11 Low, medium and high cloudiness with operational radiation (left and right) and NER (center), random overlap (left and right) and random maximum overlap (center) using operational (left) and Xu-Randall cloudiness scheme with new critical relative humidity profile (center and right), 30 hour forecast starting 00 UTC 14th December 2004.

12. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting12 Low, medium and high cloudiness Low, medium and high cloudiness, with FMR radiation scheme called with 3 hr interval (left) and 1hr interval (center and right), with maximum (center) and random overlap (right) and Xu-Randall cloudiness scheme with new critical humidity profile, 30 hour forecast starting 00 UTC 14th December 2004.

13. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting13 Comparison of the modelled 2m temperature evolution for 00 UTC run on 14th December 2004 with measured data from synoptic station with operational radiation scheme (left) including NER (center) and FMR (right). Comparison to measurements reference rand max rm+new RH XR cloud random old RH max, 1hr r-max, 1hr rand, 1hr max, 3hr r-max, 3hr rand, 3hr

14. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting14 Radiation and cloudiness results New relative humidity profile only slightly increases low cloudiness. Random maximum overlap significantly reduces the amount of clouds and amplified the diurnal variation of temperature when compared to the random overlap results. Xu-Randall cloudiness scheme gives more clouds and improves 2m temperature forecast. More sophisticated radiation schemes did not improve results. The parameterization of cloudiness seems more important than the radiation parameterization for better forecast of 2m temperature.

15. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting15 SLHD Numerical horizontal diffusion is applied along model level that follows orography, so it is not purely horizontal. Significance of physical diffusion increases with horizontal resolution, in situations with strong horizontal wind shear and statically stable situations, is more pronounced in cyclogenetic areas like Adriatic Sea. Near orography model levels are more tilted, “horizontal” diffusion acts more along the vertical. Horizontal mixing occurs between “valleys” and “mountaintops”- cloud forming on mountaintop instead of fog in the valley.

16. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting16 Twin cyclones Meteosat-8 infra-red image for January 26th 2005, 06 UTC. Cyclones over Tyrhennian and Adriatic Sea. Adriatic cyclone Tyrhennian Sea please, ignore this one it is outside of the domain

17. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting17 Twin cyclones 10m wind and mean sea level pressure obtained with numerical diffusion (top left), SLHD (top) and their difference (left), 48 hour forecast starting from 00 UTC 24th January 2005. numerical diffusion SLHD difference

18. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting18 Twin cyclones AT850 and wind obtained with numerical diffusion (top left), SLHD (top) and their difference (left), 48 hour forecast starting from 00 UTC 24th January 2005. numerical diffusion SLHD difference

19. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting19 Fog case Meteosat-8 RBG composite of channels 3.9, 10.8 and 12.0 µm for December 15th 2004, 06 UTC.

20. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting20 Fog case Low, medium and high cloudiness, numerical diffusion (left) and SLHD (right), 30 hour forecast starting from 00 UTC 14th December 2004.

21. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting21 Comparison to data Comparison of the modelled 2m temperature evolution for 00 UTC run on 14th December 2004 with measured data from synoptic station reference NER LRAUTOEV SLHD mean orog SLHD+m.o.

22. Ljubljana, 3-5 October 2005 27th EWGLAM & 12th SRNWP meeting22 Summary Semi-Lagrangian Horizontal Diffusion (SLHD) shows beneficial impact on the –reduction of the overestimated cyclone intensity, –correction of cyclone position while not altering a good intensity prediction, –improvement of fog forecast in the valleys