First results of the AROME prototype Yann Seity

First results of the AROME prototype Yann Seity (Météo-France CNRM/GMAP) 14 th ALADIN Workshop Innsbruck June 2004

Introduction Dynamics ALADIN-NH AROME 2. 5 -km (1/1) Physique Meso-NH

Plan 1. Status of the AROME prototype 2. 2 D Academic case 3. Real case : GARD 08 -09 -2002 4. Conclusion

Status of the AROME Prototype (1/1) Physics : Full physics interfaced : Micophysics, Turbulence, Radiation and Surface Only one externalized adjustment Dynamics : 2 TL and 3 TL schemes P/C scheme

2 D Academic Case (1/5) § Idealised squall line § initiated by a cold pool produced by a 0. 01 K. s-1 cooling rate applied for 10 min at low level § Wind, temperature and humidity profiles derived from a RS from COPT 81 § 2. 5 km resolution, 8 hours run § Tubulence + Microphysics

2 D Academic Case (2/5) Squall Line Case: AROME (+3 h) Meso. NH (+3 h) Theta-theta 0 Vertical velocity Relatif wind P-P 0 Relative wind P-P 0

2 D Academic Case (3/5) Squall line case: AROME (+3 h) Meso. NH (+3 h)

2 D Academic Case (4/5) A 2 D academic squall line case : AROME (+3 h) dt=7. 5 s AROME (+3 h) dt=30 s Theta-theta 0 Vertical velocity Relative wind P-P 0

2 D Academic Case Theta-theta 0 Relative wind (5/5) Vertical velocity Cloud TKE humidity Sum hydro

Real Case (1/6) GARD flood 8 -09 -2002 Simulation parameters: Size 192 x 192 points Full Physique Radiation called every 15’ Coupling every 3 h with Aladin France Begin at 12 TU 8 Septembre Time step 7. 5 s Goal : As good as referenced meso. NH simulation

Real Case (2/6) 850 h. Pa wind at 18 TU AROME Meso-NH

Real Case (3/6) Simulated radar plot at 1500 m from 13 to 18 TU AROME Meso-NH

Real Case (4/6) Vertical cross section of w at 15 TU AROME

Real Case Hydrométéores (5/6) Radar Reflectivity

Real case (6/6) Radar Reflectivity at 15 TU AROME Nîmes Radar

Real case (6/6) Time step increasment : Without P/C : 15 s OK but 30 s not With P/C : 30 s OK but 45 s not

Conclusion (1/1) üFirst comparative tests between meso. NH and AROME in 2 D or 3 D cases show quite similar results üFine analysis of AROME and Méso. NH simulations : need of diagnostics (surface, cumulated rainfalls, etc…) ü 2 D tests of increasing time step are encouraging. Remaining problems in 3 D case. (which configuration of P/C for AROME ? ) ü Code optimisation for benchmark

First results of the AROME prototype Yann Seity (Météo-France CNRM/GMAP) 14 th ALADIN Workshop Innsbruck June 2004