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Kain-Fritsch/Rasch-Kristjanson in Hirlam

Kain-Fritsch/Rasch-Kristjanson in Hirlam. With contributions from. Javier Calvo. Karl-Ivar Ivarsson & Colin Jones. Outline of the talk. Moist physics schemes in HIRLAM Reference is STRACO (Based on Sundqvist) New/optional is Kain-Fritsch & Rasch-Kristjansson

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Kain-Fritsch/Rasch-Kristjanson in Hirlam

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  1. Kain-Fritsch/Rasch-Kristjanson in Hirlam With contributions from Javier Calvo Karl-Ivar Ivarsson & Colin Jones

  2. Outline of the talk • Moist physics schemes in HIRLAM • Reference is STRACO (Based on Sundqvist) • New/optional is Kain-Fritsch & Rasch-Kristjansson • Background of new moist physics components • Review of the results of the new schemes in Hirlam • Conclusions

  3. Moist physics schemes for HIRLAM (1) • Operational scheme is called STRACO (Sass, 2002) • Sundquist type (Kuo convection and Sundquist microphysics) • Smooth transitions convective-large scale regimes • Treatment of shallow convection • Tuning for high horizontal resolutions (5-10 km) • Improvement of diagnostic cloud scheme (statistical type) • Most HIRLAM components developed with this scheme as reference. • Long operational use.

  4. Moist physics schemes for HIRLAM (2) • A scheme based on Kain-Fritsch convection and Rasch/Kristjansson is in the HIRLAM reference system since September 2004. • Three new components: • Kain-Fritsch convection • Rasch-Kristjansson condensation • Diagnostic cloud fraction based on RH

  5. Background of the new schemes Kain-Fritsch Convection • Mostly developed and used within MM5 community • Specially suitable for mesoscale middle-latitudes simulations (10-30 km resolution) including severe phenomena. • Operational use over the USA (up to 10 km resolution) • MM5 Model • Eta Model • WRF Model • Bechtold’s version of KF • MESO-NH: Extensively tested. Many cases studies from synoptic scale to CRM scales. Realistic systems • ARPEGE/ALADIN. Not able to improve the reference convection • Hirlam • RCA, Rossby Center Regional Climate Model: 20-50 km • Operational at SMHI since 2003 • Hirlam reference as option since September, 2004

  6. Hirlam modifications to the new schemes Kain-Fritsch Convection • Based on new version of KF (Kain, JAM, 2004): • Implementation similar to the one in WRF model • In HIRLAM, implemented by Colin Jones for RCA model • Several updates mainly concerning shallow convection

  7. Background of the new schemes Rasch-Kristjansson large scale condensation • Based on Rasch and Kristjansson, J. Climate, 1998 • Developed for the Community Climate Model (CAM3) where is the reference since 2004 • First introduced in Hirlam by Odegard, 1999 (HNL 33)

  8. Hirlam modifications to the new schemes Rasch-Kristjansson large scale condensation • The scheme is divided in two parts: • Condensation parameterization (water vapor ↔ condensate) following Sundquist ideas but completely recoded. • Bulk microphysics (condensate to precipitation) with and approach similar to CRM formulae. • Different physical processes are well separated • Updates and improvements more easy • For HIRLAM mainly tuning updates (Mainly by C. Jones). • Inclusion of Hirlam thermodynamics • Make the autoconversion process independent of model’s vertical resolution

  9. Hirlam modifications to the new schemes Diagnostic cloud fraction • Large scale clouds basically depend on Relative Humidity. Initially based on Slingo (1987) but completely recoded. • Convective clouds are function of convective mass-flux following Su and Krueguer (1991). • Shallow clouds are based on Albrecht (1981) as described by Jones and Sánchez (2002): • Depend on resolved RH and Cu updrafts water vapor and condensate. • There is a memory of shallow clouds that may generate precipitation through large scale microphysics.

  10. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column Model case studies • Model’s climate: Hadley circulation • Rossby Center Climate model. • Complete model case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme and observations. • Operational use at SMHI.

  11. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column Model casestudies • EUROCS Project • Model’s climate: Hadley circulation • Rossby Center Climate model. • Complete model case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme and observations. • Operational use at SMHI.

  12. SCM cases from EUROCS in which HIRLAM participated • Diurnal cycle of Sc over ocean • Diurnal cycle of shallow Cu over land • Diurnal cycle of Deep convection over land. EUROCS project • EUROCS tried to improve the representation of clouds in GCM and NWP models. • Identify systematic errors in the models. • Design ideal cases based on observations. • Compare SCM and CRM with observations • Evaluate improvements in the GCM. • Philosophy similar to GCSS intercomparisons except that EUROCS also includes simulations with the complete GCMs.

  13. LES STRACO KF/RK Diurnal Cycle of Sc over ocean Evolution of Liquid water • KF/RK and STRACO show similar behaviour: • Lack of or insuficient cloud top entrainment: • Drizzle acts to control Liquid Water: • Sensitivity to microphysics formulation.

  14. Diurnal Cycle of Shallow Cu over land LES KF/RK STRACO Evolution of Liquid water • The mass-flux approach (KF) describes better the growth and daily evolution of the clouds. • Passive cloud formulation for KFRK • As active clouds tipically not larger than 5% it is very important to include the ‘passive clouds’ which have a significant impact on radiation

  15. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column Model casestudies • EUROCS Project • Model’s climate: Hadley circulation • Rossby Center Climate model. • Complete model case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme and observations. • Operational use at SMHI.

  16. Representation of the Hadley Circulation: ‘Climate’ of KF/RK and STRACO • Hirlam run in NWP mode • Compute monthly means of H+24 forecasts • Compare with satellite observations • Comparison with other models

  17. Cross sections along the Hadley Circulation

  18. Precipitation: Comparison with TRMM satellite KF/RK STR TRMM

  19. Precipitation: Comparison with TRMM satellite Both Hirlam schemes show too much precipitation in the Sc and Shallow Cu regions

  20. Cloud Cover: Comparison with ERA ECMWF H+6 KF/RK STR ERA ECMWF H+6

  21. Deficiencies on cloud cover and LWP: specially underestimation in the Sc regions and overestimationi n the sahllow Cu KF/RK Cloud cover STR LWP

  22. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column Model casestudies • EUROCS Project • Model’s climate: Hadley circulation • Rossby Center Climate model. • Complete model case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme and observations. • Operational use at SMHI.

  23. Hirlam-Rossby Center Climate Model(Willen, Jones and Wyser, 2004) RCA3 44km 24L ERA40 • Seasonal precipitation from RCA compared to observations: • the model captures the amplitude and spatial distribution of the precipitation for all seasons

  24. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column Model casestudies • EUROCS Project • Model’s climate: Hadley circulation • Rossby Center Climate model. • Case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme and observations. • Operational use at SMHI.

  25. Finkele, 2001 (HNL 37): • Rapidly deeping cyclone from FASTEX • Experiments at 24 and 12 km • More realistic cloud patterns with KFRK. • McGraph and Finkele, 2001 (HNL 38): • Parallel runs of STRACO and KFRK • Small differences in standar scores except cloud cover • Rapidly deepening cyclones more better represented in KFRK. Cases Studies • Niemela and Fortelius, 2002 (HNL 41): • Frontal system. Experiment at 5.5 km resolutions and 40L • KFRK shows stronger updradrafts and downdrafts than STRACO • No clear adventage on using one of the schemes.

  26. A typhoon case study (COMPARE III) • H+72 integration using different initial conditions. • Comparison with observations and other models • Errors in the track prediction are small • Little impact of the resolution on the track forecast

  27. Typhoon case study: Intensity • Very rapid intensification (100 hPa/ 3 days) • - Very sensitive to initial conditions and model resolution • - Kain-Fritsch performed quite well for this case (BOLAM and HIRLAM model) STR KF/RK

  28. Typhoon case study: STRACOprecipitation (H+60) 20 km 50 km

  29. Typhoon case study: KF/RK precipitation (H+60) 20 km 50 km

  30. Precipitation as function of model resolution in the core region As expected, in the inner area (200 km around the typhoon center), convective precipitation decreases as resolution increases whereas large scale precipitation increases. Total precipitation increases increasing model resolution.

  31. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column case studies. • Model’s climate: Hadley circulation • Case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme. • Operational use at SMHI.

  32. 5 test periods on different seasons (3 months). Using Hirlam 6.2.0 NWP mode at 20km: Parallel runs • - Comparison of reference STRACO and KFRK- Scores against observations • 23 Dec- 7 Jan 2000 • 1–15 May 2001 • 1-15 Aug 2001 • 15-30 Sep 1994 • 1- 31 Oct 2002

  33. Temperature Relative Humidity KF/RK REF Comparisons against EWGLAM soundings Similar scores excepted in the humidity field

  34. Comparisons against SYNOP stations MSL Pressure Cloud Cover KF/RK STR • Only differences in MSLP and cloud cover: • Small deterioration of MSLP • Some improvemnet in cloud cover

  35. MSLP RMS against its own analysis (all periods) KF/RK REF

  36. MSLP RMS against its analysis (all periods) REF KF/RK

  37. Spain EWGLAM Precipitation against SYNOPs (all periods)

  38. October 2002 precipitation as seen by SYNOP stations and High-resolution climatic stations

  39. Upscale high-resolution observations to model resolution

  40. October 2002 precipitation: impact of the resolution

  41. October 2002 precipitation:KFRK vs REF-STRACO at 0.2 KF/RK REF

  42. Review of the results of the new moist physics (KFRK) in Hirlam • Single Column case studies. • Model’s climate: Hadley circulation • Case studies: Mainly severe weather • Parallel runs: comparison with reference STRACO moist scheme. • Operational experience at SMHI.

  43. Operational experience at SMHI(from Karl-Ivarsson, personal comunication) • KF/RK is in the SMHI operational suit since Dec, 2002 • At 0.4 and 0.2 resolutions with 40 levels • Experimental 0.1 resolution. • Only a few experiments comparing KF/RK with the reference STRACO: so no conclusion on this. • Duty forecasters seem to be very satisfied with the new scheme, specially for convective situations. • Validation of the new operational suite gave a significant improvement of the humidity forecasts (but several new modules incorporated) • It seems that Hirlam is able to add value to ECMWF forecasts in terms of clouds and precipitation.

  44. Operational experience at SMHI(Karl-Ivarsson, personal comunication) • Comparison of Hirlam 0.2, Hirlam 0.1 and ECMWF model for the period July, 7-Ago,17, 2004: True Skill Statistic

  45. Experiment at 10 km: ppt acc. 6hr H+06

  46. Experiment at 10 km: ppt acc. 6hr H+12

  47. Experiment at 10 km: ppt acc. 6hr H+18

  48. Experiment at 10 km: ppt acc. 6hr H+24

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