1. Simulations nocturnes stables à mésoéchelle pour des bassins aux latitudes moyennes J.Cuxart and M.A. Jiménez Universitat de les Illes Balears 4th Meso-NH user’s meeting, Toulouse 23-24 April 2007

2. Objective: to study the local nocturnal circulations at the basin scale under stably stratified conditions and weak pressure gradient conditions Works at UIB: → Data analysis → LES modelling (next talk) → Mesoscale modelling (methodology) Meso-NH (MASDEV4_5 and MASDEV4_6) at ECMWF Lateral conditions: analysis from ECMWF Verification against observations: AWS and satellite images (NOAA and MSG)

3. Domains MALLORCA ISLAND 125x100 grid points at 1km resolution (2 domains, nesting) DUERO RIVER BASIN 320x250 grid points at 2km resolution (1 domain) Resolution: about 1 km in the horizontal and in the vertical about 3 m close to the ground and stretched above (85 levels) Turbulence + radiation + soil + condensation schemes

4. Δ = 5 km Δ = 1 km Cases of study: 5 -6 January 1999 and 28-29 April 2005 (MSG) The Mallorca island 125 km 100 km

5. 10m WIND AT 04 UTC The Mallorca island

6. GENERATION OF KATABATIC WINDS θ (K) M (m s -1 ) TKE (m 2 s -2 ) A B A B The Mallorca island maximum wind speed at 50m

7. 1.5m TEMPERATURE AT 04 UTC The Mallorca island

8. Meso-NH NOAA The Mallorca island VERIFICATION OF THE RUNS AGAINST NOAA IMAGES

9. VERIFICATION OF THE RUNS THROUGH PDFS (I) NOAA: 2-D fields only at 2 different instants (1km) MSG: Better spatial resolution than NOAA (each 15 min) but coarser spatial resolution (4km) AWS: time series every 10min AIRPORT PDFs computed at a single instant (0330UTC) over Majorca island PDFs computed over the whole night

10. VERIFICATION OF THE RUNS THROUGH PDFS (II) The shape of the PDFS depends on:  Number of points  Horizontal resolution  Resolution of the data

11. 100m STREAMLINES AT 06 UTC 10m TEMPERATURE AT 06 UTC 500 km 640 km 100 m TOWER densely instrumented case of study: from 12 to 15 January 2003 The Duero river basin

13. Further work: continue with the study of the Katabatic and basin scale flows and their verification Use new version MASDEV4_6 installed at ECMWF Use new tools (mesonh2obs,...) to help in the verifying work Revise the soil uses of Meso-NH (CORINE) for the domains of interest and compare them against GIS or satellite images Study new domains as the Ebre river basin and Hudson valley Verify against aircraft observations AWS Pyrenees Ebre River Mediterranean Sea

14. The Duero river basin CANTABRIC SEA 100 m TOWER densely instrumented ATLANTIC SEA 640 km 500 km Case of study: from 12 to 15 January 2003

15. VERIFICATION OF THE RUNS THROUGH PDFS (III)