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Unified Model Developments 2002. Clive Wilson NWP Met Office. Outline. Configurations & Users Global and UK Mesoscale Changes Regional European Model New supercomputer Plans. Operational Versions & External Users. Global 38 levels, N216= 432x325 (~60km) UK Mesoscale
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Unified Model Developments 2002 Clive Wilson NWP Met Office
Outline • Configurations & Users • Global and UK Mesoscale Changes • Regional European Model • New supercomputer • Plans
Operational Versions & External Users • Global • 38 levels, N216= 432x325 (~60km) • UK Mesoscale • 38 levels, 0.11 deg (12km) • Stratospheric • 42 levels (~1.3km @ 100-1hpa), N48=96x73 (~300km) • Crisis models (LAMS) • Middle East, Former Yugoslavia,SW Asia • External • CGAM UK, ICM Warsaw, Thai Met Service, New Zealand, DNMI
Changes • Global • G26 16 Oct 3dvar upgrade • Increase Observation errors for AMVs • Revise thinning of ATOVS to give preference to microwave-clear over IR-clear • Use of fractional sea-ice in ATOVS processing • G27 7 August 2002 New Dynamics and HadAM4 • G28 1 Oct Introduce NOAA17 • UK Mesoscale • G27 7 August 2002 New Dynamics
Expected benefits of New Dynamics • Non-hydrostatic capability – ability to increase resolution in UK area. • Improved stability and accuracy - less noise in forecasts • Improved physics for global model - improved coupling to dynamics. • Unify physics between global and UK area - Better boundary conditions. • Better coupling with 3D-Var which was designed around new grid.
Bars show the %change in RMSE (NDHadAM4 - OP/OP) for the components, which make up the NWP index. Verification is against observations. Blue signifies Northern Hemisphere, red the Tropics and Green is the Southern Hemisphere. A negative value implies NDHadAM4 is an improvement over OP.
Typhoon Phanfone 18 August 2002
Screen temperature OP ND mean • Shadow suite (16/1-4/2), all stations forecast range forecast range rms 0 12 24 36
10-metre wind OP ND mean speed • Shadow suite (16/1-4/2), all UK stations rms vector 0 12 24 36
Relative Humidity OP ND mean • Shadow suite (16/1-4/2), all stations forecast range rms 0 12 24 36
Visibility • Shadow suite (6/12-4/2), all stations
Rainfall (skill) • Shadow suite (6/12-28/1) • v Nimrod 6-hourly accumulations
Rainfall (bias) • Shadow suite (6/12-28/1) • v Nimrod 6-hourly accumulations
ND French Storm Vt 12Z 27/12/1999 OP T+0 T+72
Danish Storm Vt 12Z 03/12/1999 ND OP T+0 T+24
Reduced NH RMSE in summer and at early FC ranges in winter Deeper extratropical cyclones Reduced temperature biases Improved stratospheric circulation statistics (eddy temperature fluxes) Reduced noise in ND forecasts. Improved radiative balance - OLR Tropical upper level wind RMSE too large (~6-10%) SH T+24 wind RMSE too large (vs analysis) - corrections ready Grid point storms at N216. Tuning of orographic and BL drag and diffusion still required. Low cloud in UK mesoscale Poor initial precipitation in UK Mes New Dynamics Summary Benefits Problems
New Regional European model • Opportunity to reorganise Operational suite • New dynamics model formulation (August 2002) • Better Global performance but double cost • 2X number of processors to keep to delivery time • Mesoscale ~same as current • relatively more efficient than global • Remove duplication of Global Preliminary/Main runs
Resources • Make full use of operational time & processors • Processors • global 288, UKmes 108 factor of 2.8 • Release duplicate Prelim/main • analysis +2 day forecast (=40min) • 60min slot (=20 min gap + “duplicate time”) • ~5X UKmes cost
Proposed Domain 548 Current UK mesoscale 320 New Euro Mes 20km resolution
00/12 00/12 2 Days P +1:50 Prelim Run 2 Days +2:40 +3:00 6 Days G Main Run +4:50 Ocean, wave, surge 2 Days P +7:50 Prelim Run 2 Days Boundary Forcing Current Operational Schedule
00/12 00/12 2 Days +1:50 Main Run part 1 2 Days +2:40 2 Days EuroRun E +3:00 +3:40 Days 2-6 Continued Main Run +4:50 Ocean, wave, surge Boundary Forcing Proposed Operational Schedule
estimated 250hPa winds Estimated Global worsening
Timetable • 5 November - Merge Prelim/Main model +digital filter intitialisation instead of incremental analysis update • but leave split of run until next year • 12 Nov -Forecast only European Model introduced • Post November -products and downstream use developed • 14 Jan - basic data assimilation • 25 March- model & DA upgrade • June 03 - Declare Euromodel operational (high risk -Exeter transition)
New supercomputer need • Improve NWP systems: • Satellite data volumes • New Dynamics • 4D-VAR • Higher resolutions • Very fine resolution mesoscale (~2km) • European Mesoscale model • Short range Ensembles • Operational Suite creaking at the seams
What are we getting? • Initially - NEC SX-6 • 30 nodes • Each node has 8 CPUs sharing 64Gb of memory • Each CPU is equivalent to approx 30 T3E CPUs • Overall performance: • 6x T3E’s for “performance work” • > 6x T3E’s for “throughput work”
And in the future • In 2005 - joined by SX-6 successor: • 15 nodes • Each CPU twice as powerful • Overall performance • 12.5x T3Es for “performance work” • >12.5x T3Es for “throughput work”
IXS NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) NODE(8 CPUs) IXS(Interconnect) FibreChannel Gigabit Ethernet FC Switch Front End12xIA64 Front End12xIA64 Mirrored filesystems User filesystems Met Office Networks The Bits
Bracknell SX-6 ExeterSX-6(A) ExeterSX-6(B) Date T3E-A T3E-B Sep 02Oct 02Nov 02Dec 02Jan 03Feb 03Mar 03Apr 03May 03Jun 03Jul 03Aug 03Sep 03Oct 03Nov 03Dec 03 1 node system Upgrade:4 nodesFront end 17/06-22/07 15 node system Move to Exeter Move to Exeter 15 node system 02/09-06/10 Move to Exeter Acceptance tests Timetable Installation
Plans 2002- 2003 • November UK Mes DA-improved covariances • December Global model & DA • January • New Dynamics in Stratospheric model • Data assimilation in Euro model • Feb-March -Global, UK mes & Euro model+DA upgrades • Transition to Exeter • Moratorium May 03 - October 03
Future Plans • 4dVar • Practicable global synoptic scale ready for test on new computer end 03 • Inclusion physical processes 04 • operational early(?) 2004 • Increased resolution • 40km , 50L Global; 10km , 50L Euro mesoscale • Physics • new gravity wave drag • new convection • new cloud (prognostic cloud and condensate)