Simulation et prevision du temps

Dominique Marbouty Head, Operations Department European Centre for Medium-range Weather Forecast [email protected]

http://www.ecmwf.int

21/03/2000 9th ORAP Forum ECMWF/DM-1

Agenda

• The current situation – What is ECMWF?: activity, requirements – Past evolution of ECMWF’s computer means – Comparison with other NWP centres • Future evolution – Requirements – Schedule – The main issues 21/03/2000 9th ORAP Forum ECMWF/DM-2

Member States Belgium Denmark Federal Republic of Germany Spain France Greece Ireland Italy Yugoslavia The Netherlands Norway Austria Portugal Switzerland Finland Sweden Turkey United Kingdom

Co-operation agreements or working arrangements with:

Croatia Iceland WMO ACMAD Hungary Slovenia EUMETSAT

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European Centre for Medium-Range Weather Forecasts Background 1967 European Council of Ministers propose co-operation in science and technology 1969 Expert group in meteorology propose ‘European Meteorological Computing Centre’ 1971 Establishment 1975 Report on ‘EMCC’ : Net benefit of £100m per annum at 1971 prices ECMWF convention in force 1978 Start of operational activities 1978 Headquarters building completed Installation of first computer system (CRAY 1-A) 1979 1983 Start of operations (N48 grid point model) T63 / L16 spectral model 1983 1985 1985 1990 1991 1992 1993 1996 1997 1999 CRAY X-MP/22, IBM data storage system T106/L19 spectral model CRAY X-MP, DEC telecommunications system (VAX) CRAY Y-MP8/8-64 T213 / L31 spectral model CRAY C90 - ocean wave forecasting Ensemble prediction system Fujitsu VPP300-C and VPP700-46 Fujitsu VPP700-116 Enhanced Fujitsu VPP system

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ECMWF in a few figures

• Participants: • Age: • Staffing: • Budget: • Model resolution: • EPS: 20 States 25 years 200 persons 25m £ 60 km 50 elements 21/03/2000 9th ORAP Forum ECMWF/DM-5

ECMWF’s principal objectives

• development of numerical models for weather forecasting • daily distribution of forecasts to its Member States • development of seasonal forecasting • collection and storage of appropriate meteorological data • allowing research staff to access these archives from remote sites • providing computer resources to Member States ECMWF/DM-6 21/03/2000 9th ORAP Forum

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IFS/ARPEGE

• NWP package developed jointly by ECMWF and Météo-France • includes forecast model, 4D-Var assimilation system, ensemble prediction system • Medium range forecast: T L 319 L60 (60 km) • 4D-Var: T L 319/T63 (60/300km) • EPS: T L 159 L40 (120km) 51 members • SF: atm T L 95 (200km) ocean 2 o x2 o x20 21/03/2000 9th ORAP Forum ECMWF/DM-9

IBM SP FUJITSU VPP700 (116 PEs) FUJITSU VPP700E (48 PEs) FUJITSU VPP300 (9 PEs) FDDI PCs SGIs SGIs FUJITSU VPP300 (4 PEs) IBM RS/6000 SGI Challenge SGI Origin 2000 VAX Router E T H E R N E T Router HP 9000 DEC WWW Router Router Firewall

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TCP/IP DECNET MEMBER STATES

9th ORAP Forum

JANET/ INTERNET

ECMWF/DM-10

ECMWF Supercomputer Growth

10,000.00

1,000.00

100.00

VPP5000/100 + VPP700 VPP700/46 10.00

C90/16 1.00

Y-MP/8 X-MP/4 0.10

XMP/2 CRAY-1 0.01

79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 Peak Performance (Gflops) Sustained Performance (Gflops) 21/03/2000 9th ORAP Forum ECMWF/DM-11

The current ECMWF’s computers

• Fujitsu VPP 700/116 peak 255 Gflops sustained 80 Gflops • Fujitsu VPP 700E/48 peak 115 Gflops sustained 35 Gflops • Fujitsu VPP 5000/38 peak 365 Gflops sustained 110 Gflops ____ _____ 735 ~ 225 • From next August • Fujitsu VPP 5000/100 peak 960 Gflops sustained 288 Gflops ____ _____ 1330 ~ 400 21/03/2000 9th ORAP Forum ECMWF/DM-12

Other NWP Centres

• UKMO SGI T3E900 /876 pk 788 Gf st ~79 Gf SGI T3E1200/636 pk 763 Gf st ~76 Gf _________ ______ 1550 Gf ~155?

Gf • DWD • NCEP SGI T3E1200/812 pk IBM SP/768 pk 974 614 Gf st Gf st ~97?

~45?

Gf • Météo-France Fujitsu VPP5000/31 pk 298 Gf st ~90?

Gf Gf 21/03/2000 9th ORAP Forum ECMWF/DM-13

The targets set for period 1999 to 2008

• an extension of the skill of the deterministic forecast, as measured by the NH 500 hPa height field reaching 60%, by one day; • a gain of one day at D+6 in the Brier skill-score for EPS-based probabilistic forecasts of moderate 850 hPa temperature anomalies (4K or larger) over Europe; • preparation by 2003 of an assessment of seasonal forecast skill over the last 40 years; • improving timeliness and reliability of product dissemination; • provision of good forecasts of severe weather towards day 4 or day 5 this requires the development of a suitable performance evaluation relating to severe weather.

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Approach

• the development of an increasingly accurate earth-system model , using efficient and economical numerical methods together with a comprehensive and exhaustively-validated physical parameterisation package; • the development of most advanced mathematical methods to extract information from in situ data and from improved data assimilation systems operational and research satellites ; employing the • the development of improved EPS techniques extended-range and seasonal forecasting.

for medium-range, 21/03/2000 9th ORAP Forum ECMWF/DM-15

Development of the operational system-2000 to 2001

• a 60-level T L 511 (40km horizontal resolution) 4D-Var data assimilation system, with analysis increments corresponding to the inner loop resolution of T L 255 (80km); • a Reduced Rank Kalman Filter (RRKF) to provide estimates of flow dependent background and analysis errors; • a 60-level T L 511 (40km horizontal resolution) deterministic model; • a 60-level T L 255 (80km horizontal resolution),100 elements, EPS model; • a 60-level T L 95 (120km horizontal resolution) atmospheric/ocean model for seasonal prediction.

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Next developments

• By 2001 - the effective utilisation of METEOSAT Second Generation geostationary satellite data will require a move towards a resolution of 40 km for the global analysis/forecast system employing 90 levels • By 2003 - full use of a 30 km 90 level system to enable effective use of data from Europe’s polar orbiting METOP satellite • By 2008 - doubling of the horizontal resolution to 20 km and increased vertical resolution will improve the exploitation of data from the high resolution satellite-borne sounders such as IASI and AIRS and other high resolution data over land 21/03/2000 9th ORAP Forum ECMWF/DM-17

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Draft schedule for the next computer

• December 2000: specifications decided by ECMWF’s Council • 2001: run Invitation To Tender (ITT) • December 2001: decision • 2002: installation, parallel run, move operations to new machine 21/03/2000 9th ORAP Forum ECMWF/DM-19

The preparation of the ITT • Facilitate competition: RAPS

– RAPS6 to be issued this May (includes 4D-Var)

• Vector / Scalar : open choice

– code adaptation is being prepared 21/03/2000 9th ORAP Forum ECMWF/DM-20

Growth in the ECMWF archives

16 14 12 10 8 6 4 2 0 2000 2001 2002 2003 2004 2005 2006 2007 2008

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Archive

ECMWF/DM-21

Conclusions

• Exploitation of the current Earth System Modelling capabilities and of the full information content of new satellite data will require substantial computer resources - the benefit will vastly improved forecast from a few days to a few seasons ahead • The HPC could be acquired provided budgets are maintained in real terms.

• Managing petabyte archives will be a major challenge.

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