Meso- γ 3D-Var Assimilation of Surface measurements : Impact on short-range high-resolution simulations. Geneviève Jaubert , Ludovic Auger, Nathalie Colombon, Véronique Ducrocq, François Bouttier CNRM/GAME Météo-France and CNRS. G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Meso-Meso-γ 3D-Var Assimilation of Surface γ 3D-Var Assimilation of Surface measurementsmeasurements: :
Impact on short-range high-resolution Impact on short-range high-resolution simulationssimulations
Geneviève JaubertGeneviève Jaubert, Ludovic Auger, Nathalie Colombon, , Ludovic Auger, Nathalie Colombon, Véronique Ducrocq, François BouttierVéronique Ducrocq, François Bouttier
CNRM/GAME Météo-France and CNRSCNRM/GAME Météo-France and CNRS
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France
Introduction
Feasibility study for:• the assimilation part of the next operational NWP high-resolution system of Meteo-France AROME • high-resolution reanalyses of the field phase of cooperative experiments
Validation on the Gard torrential event (8-9 sept.2002) and the MAP IOP08 frontal case (20-21 oct.1999)
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France
Hybrid assimilation systemFirst guess: large scale analysis (ECMWF or ARPEGE)Two domains: Mesoscale domain mesh 10 km Convective scale domain mesh: 2.5 km1 analysis or 6-hour assimilation with 1 hour step
Meso-NH configuration: Two nested models mesh: 10 and 2.5 km 3 ice types Explicit convection at 2.5 km
Aladin 3D-Var Analysis
Meso-NH model
IncrementsGuessAssimilation
cycle
Meso-NH simulation
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France
Experimental design06 UTC 12 UTC 12 UTC
24 hours Simulation
REF12
ANA12 UTC mesoscale analysisand
12 UTC convective scale analysis
12 UTC Large scale analysis
ASSIM
REF0606 UTC Large scale analysis
Assimilation step 1 hour07 08 10 11 1209
06 UTC mesoscale analysis
and06 UTC convective
scale analysis
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France
Data used in the analysesMAP IOP8 frontal case
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France
Gard torrential event
Surface data (3000 observations)surface pressure 2m temperature and humidity, 10m windhourly measurements
Radiosounding data (60 messages) Temperature, humidity, wind, geopotential06 UTC and 12 UTC
Mesoscale domain
Convective scale domain
2800 km
The background error statisticsBased on the background errors covariances used for the ALADIN analyses
Mesoscale domain (mesh 10 km)Mesoscale domain (mesh 10 km):ALADIN statistics except at low levels:larger variances except for the rotational wind geostrophic balance reduced at low levels
G.Jaubert Météo-France WSN05 5-9 september 2005 Toulouse France