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

Kain-Fritsch/Rasch-Kristjanson in Hirlam

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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 - PowerPoint PPT Presentation

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Page 1: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Kain-Fritsch/Rasch-Kristjanson in Hirlam

Javier Calvo

With contributions from

Karl-Ivar Ivarsson & Colin Jones

Page 2: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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

Page 3: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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.

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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

Page 5: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Background of the new schemes

• 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

Kain-Fritsch Convection

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Hirlam modifications to the new schemesKain-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

Page 7: Kain-Fritsch/Rasch-Kristjanson in Hirlam

• 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)

Background of the new schemesRasch-Kristjansson large scale condensation

Page 8: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Hirlam modifications to the new schemesRasch-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

Page 9: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Hirlam modifications to the new schemesDiagnostic 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.

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• 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.

Review of the results of the new moist physics (KFRK) in Hirlam

Page 11: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Review of the results of the new moist physics (KFRK) in Hirlam

• Single Column Model case studies• 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.

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• 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.

EUROCS project

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.

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• KF/RK and STRACO show

similar behaviour:

• Lack of or insuficient cloud top entrainment:

• Drizzle acts to control Liquid Water:

• Sensitivity to microphysics formulation.

Diurnal Cycle of Sc over ocean

KF/RK

STRACO

LES

Evolution of Liquid water

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• 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

LES

STRACO

KF/RK

Diurnal Cycle of Shallow Cu over land

Evolution of Liquid water

• The mass-flux approach (KF) describes better the growth and daily evolution of the clouds.

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Review of the results of the new moist physics (KFRK) in Hirlam

• Single Column Model case studies• 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.

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• Hirlam run in NWP mode

• Compute monthly means of H+24 forecasts

• Compare with satellite observations

• Comparison with other models

Representation of the Hadley Circulation: ‘Climate’ of KF/RK and STRACO

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Cross sections along the Hadley Circulation

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Precipitation: Comparison with TRMM satellite

KF/RK STR

TRMM

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Precipitation: Comparison with TRMM satellite

Both Hirlam schemes show too much precipitation in the Sc and Shallow Cu regions

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KF/RK

STR

ERA ECMWF H+6

Cloud Cover: Comparison with ERA ECMWF H+6

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KF/RK

STR

Cloud Cloud covercover

LWPLWP

Deficiencies on cloud cover and LWP: specially underestimation in the Sc regions and

overestimationi n the sahllow Cu

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Review of the results of the new moist physics (KFRK) in Hirlam

• Single Column Model case studies• 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.

Page 23: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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

Page 24: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Review of the results of the new moist physics (KFRK) in Hirlam

• Single Column Model case studies• 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.

Page 25: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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.

• 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.

Page 26: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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

Page 27: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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)

KF/RK

STR

Page 28: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Typhoon case study: STRACO precipitation (H+60)50 km 20 km

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

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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.

Page 31: Kain-Fritsch/Rasch-Kristjanson 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.

Review of the results of the new moist physics (KFRK) in Hirlam

Page 32: Kain-Fritsch/Rasch-Kristjanson in Hirlam

5 test periods on different seasons (3 months). Using Hirlam 6.2.0

• 23 Dec- 7 Jan 2000

• 1–15 May 2001• 1-15 Aug 2001• 15-30 Sep 1994• 1- 31 Oct 2002

NWP mode at 20km: Parallel runs

- Comparison of reference STRACO and KFRK- Scores against observations

Page 33: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Comparisons against EWGLAM soundings

Temperature Relative Humidity

Similar scores excepted in the humidity field

REF

KF/RK

Page 34: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Comparisons against SYNOP stations

MSL Pressure Cloud Cover

STRKF/RK

Only differences in MSLP and cloud cover:• Small deterioration of MSLP• Some improvemnet in cloud cover

Page 35: Kain-Fritsch/Rasch-Kristjanson in Hirlam

MSLP RMS against its own analysis (all periods)

KF/RK REF

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MSLP RMS against its analysis (all periods)

KF/RK REF

Page 37: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Precipitation against SYNOPs (all periods)

SpainEWGLAM

Page 38: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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

Page 39: Kain-Fritsch/Rasch-Kristjanson in Hirlam

Upscale high-resolution observations to model

resolution

Page 40: Kain-Fritsch/Rasch-Kristjanson in Hirlam

October 2002 precipitation: impact of the resolution

Page 41: Kain-Fritsch/Rasch-Kristjanson in Hirlam

October 2002 precipitation:KFRK vs REF-STRACO at 0.2

KF/RK

REF

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• 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.

Review of the results of the new moist physics (KFRK) in Hirlam

Page 43: Kain-Fritsch/Rasch-Kristjanson in Hirlam

• 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.

Operational experience at SMHI(from Karl-Ivarsson, personal comunication)

Page 44: Kain-Fritsch/Rasch-Kristjanson in Hirlam

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

Page 45: Kain-Fritsch/Rasch-Kristjanson in Hirlam
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Experiment at 10 km: ppt acc. 6hr H+06

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

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

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

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Page 51: Kain-Fritsch/Rasch-Kristjanson in Hirlam

High-resolution observations

Page 52: Kain-Fritsch/Rasch-Kristjanson in Hirlam

• The new moist physics scheme based on Kain-Fritsch convection and Rasch-Kristjansson large scale condensation has been tested in Hirlam.

• In terms of standard scores no big difference with reference STRACO scheme a part from:– Slight deterioration in MSLP probably caused by a tendency to over-

intensification of cyclonic systems. – Slight improvement in cloud cover– Improvement in the humidity profiles– Similar scores of precipitation:

• STRACO better for small ppt amounts (< 1 mm/day)• KF/RK probably better for ppt 3-30 mm/day• More clear improvement in southern regions probably linked to the larger number of

convective situations.

• From case studies it seems that KFRK tends to produce more realistic cloud and precipitation patterns.

Conclusions

Page 53: Kain-Fritsch/Rasch-Kristjanson in Hirlam

• Operational experience at SMHI very satisfactory• KFRK takes about 20 % more computer time than the

reference STRACO.– Still pending the vectorization of the code: external asistance is planned.

• Some clearly identified problems:– Excess of drizzle.– Cloud cover formulation

• Statistical cloud scheme• Moist turbulence

• We have started testing KFRK at 10 km resolutions.• In the near future we should evaluate its performance at lower

resolutions.– Probably further tuning is needed

Conclusions

Page 54: Kain-Fritsch/Rasch-Kristjanson in Hirlam

The End