Simulations nocturnes stables à mésoéchelle pour des bassins aux

latitudes moyennes

J.Cuxart and M.A. JiménezUniversitat de les Illes Balears

4th Meso-NH user’s meeting, Toulouse 23-24 April 2007

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)

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

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

10m WIND AT 04 UTC

The Mallorca island

GENERATION OF KATABATIC WINDS

θ (K)

M (m s-1)

TKE (m2 s-2)

A B

A

B

The Mallorca island

maximumwind speed

at 50m

1.5m TEMPERATURE AT 04 UTC

The Mallorca island

Meso-NH NOAA

The Mallorca island

VERIFICATION OF THE RUNS AGAINST NOAA IMAGES

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

VERIFICATION OF THE RUNS THROUGH PDFS (II)

The shape of the PDFS depends on:

Number of pointsHorizontal resolutionResolution of the data

100m STREAMLINES AT 06 UTC10m 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

The Duero river basin

Further work: continue with the study of theKatabatic 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

PyreneesEbre River

Mediterranean Sea

The Duero river basin

CANTABRIC SEA

100 m TOWER densely instrumented

AT

LA

NT

IC S

EA

640 km5

00 k

m

Case of study: from 12 to 15 January 2003

VERIFICATION OF THE RUNS THROUGH PDFS (III)