Computing at Météo-France CAS 2003, Annecy 1.News from computers 2.News from models

Fujitsu VPP 5000/31 dec 1999 – june PE Gflops 208 Gbytes main memory Crossbar 2x1,6 GB/s CAS 2003, Annecy

VPP 5000/64 and VPP 5000/60 june 2003 – sept 2006 Research system : 64 PE Gflops 300 GBytes main memory Operations system : 60 PE 576 Gflops 280 GBytes main memory CAS 2003, Annecy

Final configuration SYS-OP (60)SYS-RD (64) 3400 GB 2680 GB File server HIPPI switch CAS 2003, Annecy HIPPI switch 2 HIPPI links

Météo-France computing centre CAS 2003, Annecy HIPPI 800 Mbit/s Switching bandwith 64 Gbit/s STK silos 150 TB SGI O2K H-P servers Operations & development Workstations Fujitsu VPP’s

Historical point of view Cray 2 C98-4 Cray 2 C98-8 J916 VPP700E VPP VPP VPP CAS 2003, Annecy

Performance and the Moore law CAS 2003, Annecy

Archived data volume and the Moore law CAS 2003, Annecy

Archiving system main requirements CAS 2003, Annecy Phase A (march 2004) : 230 TB, 8.5 M files, I/O : 2.5 –5.2 TB/day Phase B (sept 2004) : 360 TB, 12 M files, I/O : 3.4 – 7.1 TB/day Phase C (sept 2005) : 560 TB, 17 M files, I/O : 4.5 –9.4 TB/day During all three phases : 4 days on disk cache 75 % of data must be accessed in less than 45 seconds 100 % of data must be accessed in less than 340 seconds

Computing at Météo-France part 2 : News from models CAS 2003, Annecy

Integrated Forecasting System A numerical weather prediction system developed and supported by Météo-France and the European Centre (ECMWF) Includes all contituents needed for global numerical prediction : A global spectral model (and associated tangent linear and adjoint models) 3D et 4D-VAR global assimilation etc Action de Recherche Petite Echelle Grande Echelle

CAS 2003, Annecy ECMWF (European Centre for Medium-range Weather Forecast) Reading – United Kingdom Global spectral model T511, 60 levels (up to 0.1 hPa). « Linear » (lat/lon) grid, 35 to 40 km. « Semi-lagrangian, semi-implicit » temporal integration, time step 20’. Forecasts up to 10 days, starting at 12 UTC every day 4D-VAR assimilation on a 12h window, through 2 minimisations at T159 (increment resolution) Ensemble forecast (EPS - Ensemble Prediction System) through 51 integrations of the same model, with resolution T255 / 40 levels

CAS 2003, Annecy Grid for the ARPEGE model The ARPEGE global model Global spectral model T L 358 C2.4, 41 levels Associated grid: 23 km (France)  133 km (antipodes) Representation on the globe with stretching and turning of the pole over the interest zone Collaboration with ECMWF

CAS 2003, Annecy The ARPEGE-Tropiques model Uniform resolution - horizontal grid without stretching (T L 359 grid) - vertical levels unchanged (41 levels) Run once a day from 00 UTC up to 72h range

CAS 2003, Annecy The ALADIN project Genesis Project started by Météo-France in 1990 A mutually beneficial collaboration with National Meteorological Services of Central and Eastern Europe concerning numerical prediction Acronym: Aire Limitée, Adaptation dynamique, Développement InterNational = Limited Area, dynamical Adaptation, InterNational Development

CAS 2003, Annecy The ALADIN project Different operational domains

CAS 2003, Annecy The Aladin-France limited area model A spectral model Domain: –a square 2740 km in side, centered on the point of maximal resolution of Arpège Vertical levels: –same as Arpège (41) Horizontal resolution –(9 km) ~ 2.5 × max resolution in Arpège Coupling: –applied every three hours to the global model Arpège

Principles of 4D-VAR assimilation 9h12h15h Assimilation window JbJb JoJo JoJo JoJo obs analysis xaxa xbxb corrected forecast previous forecast

CAS 2003, Annecy A short description of the 4D-VAR used at Météo-France (Toulouse) since June 2000 Minimization window 6h (maximum) INCREMENTAL technique: increments are evaluated by 2 minimizations at T107 and T149 (c=1) for the T358/c2.4 model Structure functions are not separable OBSERVATIONS WE USE: conventional, satellite winds, ATOVS radiances (no diffusiometer data) Weak constraint based on digital filters (also used to smoothen the trajectory after the last minimization)

CAS 2003, Annecy Operational use of models at Météo-France (June 2002) ARPEGE model (variable mesh), routine run 4 times a day –starting 00h UTC, until 96h –starting 06h UTC, until 42h –starting 12h UTC, until 72h –starting 18h UTC, until 30h Uniform ARPEGE model, routine run once a day –starting 00h UTC, until 72h ALADIN/France model, routine run 4 times a day –coupled to the corresponding ARPEGE model that gives boundary conditions and initial conditions, until the same forecast ranges Initial conditions are given by a 4D-VAR assimilation –run on 6h long time windows, centered on each of 00, 06, 12 and 18h UTC. –ARPEGE/Tropiques has its own 4D-Var. –Digital Filter Initialisation (DFI) is used for ARPEGE and ALADIN.

CAS 2003, Annecy Other operational models Oceanography : the MERCATOR project –North-Atlantic & Mediterranean sea : high resolution model (1/15°) –Global ocean : low resolution model (2°) –6 PEs (8 GB), 6 hours, 1week ( Ocean wave models Pollutant dispersion models

CAS 2003, Annecy Research models Climate model : ARPEGE-Climat –T L 63 or T L 159C2.5 –31 or 60 levels –T L 63 L31 used for seasonal forecasting Mesoscale model : MESO-NH –Mesoscale non-hydrostatic model –Joint development with Laboratoire d’Aérologie (Université de Toulouse Paul Sabatier) (

CAS 2003, Annecy Météo-France plans for concerning Numerical Weather Prediction Optimization of the ARPEGE-ALADIN system mainly for physics, observation use and assimilation algorithms AROME project (Application de la Recherche à l’Opérationnel à Méso-Échelle = Applying Research to Operational use at Meso Scale) NWP system with a 2-3 km horizontal mesh over France in about Target more concern for short-range prediction of dangerous phenomena (eg. precipitations), together with a greater coordination with other organizations using such predictions (eg. hydrologist)

CAS 2003, Annecy Météo-France cooperations concerning NWP ECMWF ALADIN community HIRLAM EUMETSAT (SAF) Spatial Agencies

CAS 2003, Annecy AROME PROJECT NH model based on existing dynamics in ALADIN. Largely derived from Meso-NH for physical parameterizations. Specific meso-scale data assimilation system (inspired from existing ALADIN 3D-VAR to start with).

CAS 2003, Annecy Regional use of observations for AROME Priority on infra-red radiances and imagery from new satellites, and on radar observations. Use of all surface regional and national networks Use of other satellite data: micro-waves, GPS (especially ground-based), lidar winds.

Computing at M-F THANKS CAS 2003, Annecy