Transcript HIRLAM Use of the Hirlam NWP Model (James Hamilton -- Met Éireann)

HIRLAM
Use of the Hirlam NWP Model
at Met Éireann (Irish Meteorological Service)
(James Hamilton -- Met Éireann)
COMPUTER SYSTEM and VERSIONS of HIRLAM
IBM RS/6000 SP : 9-nodes each with 4-CPU’s
• 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
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
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
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
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
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]
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]
FUTURE PLANS …
Purchase small experimental Linux-Cluster
• Budget of approx Euro 50k
• Use as backup for main computer [Operational Hirlam]
• Gain experience with Linux clusters
Investigate MOS/Neural-Nets for Post-Processing
Use Hirlam as input to Point Data-Base
Thank You