HIRLAM

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HIRLAM Use of the Hirlam NWP Model at Met
Éireann (Irish Meteorological Service) (James
Hamilton -- Met Éireann)
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• COMPUTER SYSTEM and VERSIONS of HIRLAM
• IBM RS/6000 SP 9-nodes each with 4-CPUs
• Operational Hirlam 438x284 grid pts 31-levels
• Nested Hirlam 222x210 grid pts 40-levels
• LINUX PC Twin Xeon Processors 2.0Ghz
• Backup Hirlam 218x144 31-levels
• LINUX PC Twin Xeon Processors 500Mhz
• Hourly Hirlam 97x98 grid pts 24-levels
• LINUX Cluster Nine Twin Xenon Processors
  3.2GHz
• Operational Hirlam Test mode

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• OPERATIONAL HIRLAM IBM RS/6000 SP
• HIRLAM 5.0.1 with 3DVAR
• 3-Hour assimilation cycle with 48-hour forecasts
  every 6-hours
• Rotated lat/long 0.15x0.15 grid with 438x284
  grid points
• Hybrid eta coordinates with 31-levels
• CBR vertical diffusion scheme Sundqvist
  condensation scheme
• STRACO cloud scheme Savijarvi radiation scheme
• Digital filter initialisation
• Two time-level Semi-Lagrangian semi-implicit
  scheme
• Use of frame boundaries from ECMWF

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• BACKUP HIRLAM LINUX-PC Dual 2.0Ghz CPU
• HIRLAM 4.3.5 with OI-Analysis
• 3-Hour assimilation cycle with 48-hour forecasts
  every 6-hours
• Rotated lat/long 0.30x0.30 grid with 218x144
  grid points
• Hybrid eta coordinates with 31-levels
• SAME AREA AS OPERATIONAL HIRLAM

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• NESTED HIRLAM IBM RS/6000 SP
• HIRLAM 6.0.0 with 3DVAR
• 3-Hour assimilation cycle with 24-hour forecasts
  every 6-hours
• Model runs at intermediate hours 03Z, 09Z,
  15Z, 21Z
• Rotated lat/long 0.12x0.12 grid with 222x210
  grid points
• Hybrid eta coordinates with 40-levels
• Kain-Fritsch/Rasch-Kristjansson
  convection/condensation scheme
• ISBA surface scheme
• Output post-processed with MOS

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• HOURLY HIRLAM ... LINUX-PC Dual 500Mhz CPU
• HIRLAM 4.3 with OI Analysis
• Hourly assimilation cycle with hourly analysis
  and 3-hour forecast
• Rotated lat/long 0.15x0.15 grid with 97x98 grid
  points
• Hybrid eta coordinates with 24-levels
• Analysis shown on public web-site

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• OPERATIONAL USES of HIRLAM
• General Forecasting
• Forecast guidance out to 48-hours
• WAM wave model
• Forecast 10-metre winds used to drive model
• Roadice Prediction System
• Forecast parameters are used as first guess for
  human forecaster
• SATREP
• Overlay on satellite plots ZAMG SATREP analysis
  scheme

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RESEARCH ACTIVITIES Better Specification of
B.C.s for NWP models Operational Implementation
of Nested System Regional Climate Analysis
Modelling Prediction Centre Community Climate
Change Consortium for Ireland RCAMPC and C4I
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• EXPERIMENTS with LINUX CLUSTER
• Purchased small experimental Linux-Cluster
• Dell PowerEdge 1750 Twin Xeon nodes rack
  mounted
• 1 x Master node 2.8GHz, 4Gbytes
• 9 x Compute nodes 3.2GHz, 2Gbytes
• Compute nodes in 3x3 2-dimensional torus
  Dolphin cards
• RedHat ES-3/WS-3 PGI compilers Intel compilers
• Scali MPI connect, Scali TCP connect, Scali
  Manage
• Original cluster had 6-nodes upgraded to
  9-nodes

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• EXPERIMENTS with LINUX CLUSTER
• Running Operational Hirlam on Cluster 9-node
• Hirlam 5.0.1 with 3DVAR identical to
  operational system
• Forecast takes 62 mins on IBM/SP 71 mins on
  cluster
• 3DVAR takes 15 mins on IBM/SP 9 mins on cluster
• Full run takes 77 mins on IBM/SP 80mins on
  cluster
• Therefore 9-node cluster is as fast as IBM/SP
• Experience with Cluster Generally Positive

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• FUTURE PLANS for CLUSTER .
• Investigate Use of Intel Compilers and Libraries
• Should be faster for running Hirlam
• Use Cluster as test-bed to implement latest
  Hirlam 6.4
• Use Cluster to prepare benchmark for new
  mainframe
• Replace Mainframe end of 2006 / start of 2007

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FUTURE PLANS Investigate Options to Replace
Mainframe in 2006 Get Hirlam 6.4 Running on
Cluster Investigate MOS/Neural-Nets for
Post-Processing Use Hirlam as input to Point
Data-Base
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Thank You