A CRCM5 Description

Arctic System Model Workshop IIIUQÀM, MontréalBernard Dugas & Katja WingerEnvironment Canada/RPNJuly 16, 2009

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Where does the CRCM5 come from ?

Examples of runs done with CRCM5 / GEM-LAM

GEM, GEM/DM, GEM-LAM GEMCLIM, MC2 CGCM

Dependence on domain size and Using Spectral Nudging

High resolution experiments

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Atmospheric modelsat Environment Canada (EC)

Atmospheric Science and Technology Directorate

CGCM GEM

Model for weather forecasting

Model forclimate change

studies

CRD/CCCma(Victoria)

MRD/RPN(Dorval)

CGCM (Canadian General Circulation Model)CRD (Climate Research Division)CCCma (Canadian Centre for Climate Modelling and Analysis)

Monthly and seasonal

forecasting

GEM (Global Environmental Multiscale)MRD (Meteorological Research Division)RPN (Recherche en prévision numérique)

GEMCLIM

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GEMCLIMGEMCLIM is the climate configuration of Environment Canada's

forecast model GEM (Global Environmental Multiscale)

GEMCLIM was originally developed to study systematic errors of the forecast model GEM and is routinely run at RPN as a validation tool.

The model is used operationally for monthly and seasonal forecasting. As such it is fully supported by Environment Canada

global uniform

limited areaLAM

global variable

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GEM/CRCM5 timelinesV1.0.0 (EC, 1998) GEM First (operational forecast) version

(Côté, J. et al., MWR 1998a and b)V2.0.0 (EC, 2000) GEM/DM MPI enabled GEM (inspired by MC2)V3.0.1 (EC, 2002) Non-hydrostatic dynamics option

(Yeh, K.-S., et al., MWR 2002)V3.1.2 (EC, 2004) GEM-LAM LAM configuration (largely based on MC2)V3.3.0 (EC, 2007) 4DVar Operational 4D Var implementation

(Gauthier, P. et al., MWR 2007)

V4.0.x (EC, 2009) VStag Vertical staggering (nearly complete)

GEMCLIM v3.2.2 => CRCM5.0.0 (UQÀM, 2005; intro to GEMCLIM) GEMCLIM v3.3.0 => CRCM5.0.1 (UQÀM, 2007; extensively used by students and post-docs)

GEMCLIM v4.0.x => CRCM5.1.0 (UQÀM, 2010; will include support for CGCM physics)

Note that the main difference between GEM and GEMCLIM is in thescripts used by the two models: There are few differences in theirdynamics and physics libraries and +95% of the code is shared.

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GEMCLIM

MRD/RPN(Dorval)

dynamics

physics

CRCM5at UQAM / Ouranos

Global and regional, current and futureclimate scenarios

CGCM

CRD/CCCma(Victoria)

dynamics

physics

dynamics

physicsphysics

dynamics

physicsphysics

CRCM5

UQAM / Ouranos(Montreal)

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Time stepping: Fully implicit, two-time level (with 2 Crank-Nicholson iterations)

Arakawa horizontal C-grid (U staggered in x-axis and V staggered in y-axis)

Charney-Phillips vertical staggering (Temp, moisture and W on half levels)

Semi-Lagrangian advection (absolutely stable)

Physic parameterization are treated slab-wise (2D in x-z plane)

CRCM5Numerics Highlights

This implies that the CRCM5 time step need only be determined by thedesired precision (of its physics, for example) and not by the numerical stabilityconstraints of its dynamics: Courant numbers above two or three near the upper

boundary can be easily accommodated. Note that Courant numbers below 1should still be the norm in the troposphere. We now can use a 60 minute time

step when running global 1,5° simulations and 20 minute at 0.5°.

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CRCM5 ERA40 Diff

Winter

Summer

Arctic SLP, Smaller Domain, 1983-2002 (next slides from M. Qian)

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A suite of CRCM5/GEM integrations are being compared to evaluate the overallperformance of the model in representing Arctic climate processes.Before coupling LAM model to an Arctic Regional Ocean Model.

In the next set of results 4 model runs are compared to ERA40.

1. CRCM5-LAM (0.5°) forced by ERA40

2. CRCM5-LAM (0.5°) forced by LBCs from a GEM-Global integration at 2°

3. CRCM5-Variable resolution grid. With the high resolution telescoped region of the global grid being at 0.5° resolution and covering almost the exact same area as the CRCM5-LAM runs in 1 and 2 above. The outer regular region of the global-variable grid is at 2° resolution

4. CRCM5-GLOBAL, uniform resolution at 2°

All runs used AMIP SSTs for the period 1979-2004, CRCM5 version 5.0.1

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Piloted by ERA40

Piloted by GEM Global

2.0 DEG

CRCM5Variable

GEM Global

2.0 DEGERA40

Winter SLP, Larger Domain, 1979-2001

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No nudging Nudging UV

Winter SLP (DJF 1978) differences between CRCM5 and ERA40

What happens when Spectral Nudging is used ?

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Example of high-res work at EC with GEM-LAM (project UNSTABLE config, courtesy of J. Milbrandt)

Daily 12-hour forecasts

1-km driven by 2,5-km

Non-hydrostatic models

1-km: 412x482x58, 30s

2,5-km: 648x470x58, 60s

Uses proposed Vancouver Olympic setup

Investigation of convective initiation and forecasting of deep convective storms in south-central Alberta from July to the end of September ‘09

DRAFT – Page 13 – April 22, 2023

Merci / Thank you