Hélène Côté and Daniel Caya Climate Simulations Group Consortium Ouranos Variability and...

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Hélène Côté and Daniel Caya Climate Simulations Group Consortium Ouranos Variability and Extremes in the CRCM Development of Scenarios of Climate Variability and Extremes: Current Status and Next Steps Victoria, 16-17 October 2003

Transcript of Hélène Côté and Daniel Caya Climate Simulations Group Consortium Ouranos Variability and...

Hélène Côté and Daniel Caya

Climate Simulations Group

Consortium Ouranos

Variability and Extremes in the CRCM

Development of Scenarios of Climate Variability and Extremes: Current Status and Next StepsVictoria, 16-17 October 2003

Outline• Current status of CRCM

– Policy Run II vs Policy Run III– Production runs with version 3.6.1– Preliminary results (the first 5 years of the 25-year run)– Next operational version: CRCM 3.6.3– Development of CRCM 4.0

• Variability issues in regional climate modelling• Modelling the extremes

– The data we have– What we plan to do

• Validation issues• How to improve the model

From Policy Run II to Policy Run III 3.5.1 vs 3.6.1

Radiation Fouquart and Morcrette unchanged

Land surface Beautified Bucket ( 1 layer + force-restore)

unchanged

Convection Kain-Fritsch (1990) Bechtold-Kain-Fritsch (Bechtold et al 2001)

Clouds F (relative humidity) F (relative humidity) + convective clouds

Boundary layer Bulk transfert, mixing lengh-K unchanged

Atmospheric composition

Specified [O3] [CO2] unchanged

Nesting Davies relaxation Spectral nudging

( Biner et al 2000 , Denis et al)

SSTs From Monthly GCM values From Daily GCM values or AMIP obs.

Lake Model No Mixed-layer (Goyette et al 2000)

Leap-year No Yes

New features Implicit treatment of Tg

Atmospheric budget

Current Simulations Configuration

• 45 km grid point spacing• 193 x 145 grid points• 29 vertical levels• Lid: 30 km • Archival : every 6 hours (pcp every timestep)

• Transient CO2

• Spinup period: 2 years

• Approx. 1 month CPU time per simulated year ….

• 5.7Gb of model outputs per simulated month….

Topography(m)

Policy Run IIdomain

Current SimulationsDriving data

Ocean Period Spectral nudging

CRCM Done(14/10/03)

NRA-1 AMIP 1973-1999

yes 3.6.1 133 / 364

NRA-1 AMIP 1973-1999

no 3.6.1 95 / 364

CGCM2  is92a 

CGCM2 1968-1994

yes 3.6.1 92 / 364

CGCM2 is92a

CGCM2 2037-2063

yes 3.6.1 90 / 364

CO2 Equivalent Concentration

IS92a CRCM

– CRCM CGCM2, 1968 -1994, 2037-2063

Precipitation rate (mm/day)5-year mean: Summer

CRCM/NCEP

CRU2

CRCM-CRU2

CRU2: Climatic Research Unit TS 2.020.5°X 0.5° (Mitchell et al. 2003)

Precipitation rate (mm/day)5-year mean: Winter

CRCM/NCEP

CRU2

CRCM-CRU2

Maximum Screen Temperature (ºC) 5-year mean: Summer

CRCM/NCEP

CRU2

CRCM-CRU2

Minimum Screen Temperature (ºC) 5-year mean: Summer

CRCM/NCEP

CRU2

CRCM-CRU2

CRCM Version 3.6.3

• Improve some biases of 3.6.1 related to the boundary layer: Retun the control from the planetary waves Too warm (Tmin) and too wet (pcp)

1-layer bucket too deep and very wet

Excessive cloud cover(Tmin too high)Too much evaporation

Too much preciptation

Planned SimulationsDriving data

Ocean Period Spectral nudging

CRCM Start

CGCM2 scenario *

CGCM2 scenario *

1xCO2

2xCO2

yes 3.6.3 Early 2004

CGCM2 scenario *

CGCM2 scenario *

1xCO2

2xCO2

yes 3.6.3 Early 2004

GCMx GCMx 1xCO2 2xCO2

yes 3.6.3 Early 2004

*We have to choose from CGCM2 simulations based on different CO2 emission scenarios.

GCMx: A different GCM

CRCM 4.0

• Prototype in development in collaboration with the CRCM Network (R.Laprise et al)– MC2 dynamics + GCMIII physics

• Ed Chan MSC, Virginie Lorant CCCma

– All CRCM physics and features need to be implemented

– Prototype to be completed in early 2005

Variability

• Longer timeserie to assess variablity– 25 years simulations instead of 10 years

• 2 compoments of the variability:– Intramonthly (seasonal) vs Interannual variability

– Intramonthly variability: difficult to validate due to a lack of temporal resolution of gridded observed datasets

• Results : Validation of interannual variability

Precipitation Rate (mm/day)5-year Interannual Standard-Deviation

WinterCRCM/NCEP

CRU2

CRCM-CRU2

Maximum Screen Temperature 5-year Interannual Standard-Deviation

WinterCRCM/NCEP

CRU2

CRCM-CRU2

Minimum Screen Temperature 5-year Interannual Standard-Deviation

WinterCRCM/NCEP

CRU2

CRCM-CRU2

CRCM monthly extremes

• Precipitations extremes : computed from precipitation archived every timestep (15 min)– Highest precipitation rate for different durations– Wet days for different thresholds– Dry days for different thresholds– Precipitation histogram

• Daily extremes of specific humidity (screen)• Daily screen temperature extremes• Highest gusts at the lowest level of the model

CRCM climate extremes(all in early stage of development)

• Records of the simulation

• Normals of the simulation

• Climate indices (Stardex, etc…)

• Precipitation histograms

• Temperature distributions

5-year January Daily Precipitation Histogram nearest gridpoint vs station data: Victoria

• From the 0.2 mm threashold– 124 / 155 rain days in CRCM

• 3 events above 25 mm during the simulation

• On average, – MSC obs: 17.8 / 31 (57%) rain days– CRCM : 24.8 / 31 (80%) rain days

• Precipitation too frequent

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5-year January Daily Precipitation Histogram nearest gridpoint vs station data: Kuujuaq

• From the 0.2 mm threashold– 100 / 155 rain days in CRCM

• 0 event above 25 mm during the simulation

• On average, – MSC obs: 15.4 / 31 (49.6%) rain

days– CRCM : 20.0 / 31 (64.5%) rain

days• Precipitation too frequent [0.2-5[

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Validation issues• Gridded climatologies

– Lack of resolution– Lack of temporal resolution – Lack of variables– Lack of information about the topography (except

CRU)

• CRCM – Limited time-series– Grid point vs station data– Interpolation of datasets on the CRCM grid

Improving regional climate models

• Better representation of surface caracteristics– variables used by land surface scheme

• Include smaller lakes – bathymetry, lake surface temperature, ice

– from 1968-1999

• Better parameterisations• CRCM ensembles