RCM Characteristics

Major characteristics of regional climate models used in NA-CORDEX

 CanRCM4CRCM5
(OURANOS)
CRCM5
(UQAM)
HIRHAM5RCA4RegCM4WRF
Dynamics Semi-Lagrangian Hydrostatic Semi-Lagrangian Hydrostatic Semi-Lagrangian Hydrostatic HIRLAM Semi-Lagrange Hydrostatic Semi-Lagrangian Hydrostatic Non-hydrostatic, Compressible
Land Surface Model CLASS2.7 CLASS3.5+ CLASS3.5+ ECHAM5 RCA LSS BATS NOAH
LSM Input Databases GLC2000 USGS vegetation & lake fraction; ECOCLIMAP sand & clay; Webb et al. 1993 depth to bedrock; Kourzeneva lake depth; lake fractions adjusted to represent reservoirs and lakes and to better define Great Lakes USGS vegetation & lake fraction; ECOCLIMAP sand & clay; Webb et al. 1993 depth to bedrock; Kourzeneva lake depth Fixed seasonally varying LAI ECOCLIMAP USGS Global Land Cover Character-ization USGS 24-category data
Driving Ocean BC Variables
(ts/tos, sea ice)
SSTs, sea-ice thickness, sea-ice fraction SST, SIC SST, SIC SST, SICE SST, sea ice tos

GFDL: tos, sic;
MPI: tos, sic;
HADGEM: tos, no sic

Sea Ice Character-istics thickness and fraction simple thermodynamic simple thermodynamic prescribed two-layer temperature, constant thickness inferred from tos GFDL & MPI: sea ice provided as LBC; HADGEM: sea ice threshold set to 272.0 K (sea ice present at threshold); fractional sea ice used if sic available as LBC
Lake Model Character-istics prescribed from driver FLake FLake No lake model; interpolate lapse-rate corrected SST for lakes > 0.5 gridbox FLake Hostetler et al. (1993) lake model Default WRF interpolation from nearby ocean SSTs
Sub-Grid Lakes no yes yes no yes no no
Thermal / Water Layers N/A 17 to 15m soil depth, +1 for snow / soil to depth of bedrock, +1 for snow 26 to 60m 5 / 1 (+snow) 5 / 3 3 / 3, 1 for snow N/A
Vegetation Types 4 4 (plus urban and bare soil) 4 (plus urban and bare soil) 75 classes 12 generic PFTs 20 surface types, 12 soil types 24 types
Boundary Layer Parameter-ization Bulk Richardson Formulation Delage 1997 Delage 1997 ECHAM5 TKE scheme with diagnostic mixing length and moist processes Holtslag (1990) MYJ
Explicit Moist Physics Prognostic cloud liquid water and ice, statistical cloud scheme, interactive with aerosols Sundqvist Sundqvist Prognostic liquid water and ice Prognostic equation for total cloud water mixing ratio, diagnostic cloud fraction based on threshold relative humidity SUBEX scheme, Pal et al (2000) WSM3
Cumulus Parameter-ization Mass flux scheme for shallow and deep convection Kain and Fritsch Kain and Fritsch Tiedke, Nordeng Modified Kain-Fritsch Grell scheme with Fritsch-Chappell type closure over land, Emanuel scheme over oceans Kain-Fritsch (cu_physics=1)
Vertical Coordinate Hybrid sigma-pressure 58 hybrid levels, top at 10 hPa 58 hybrid levels, top at 10 hPa Hybrid, 31 levels Hybrid sigma-pressure, 40 levels Sigma, 18 levels Terrain-following hydrostatic pressure coordinate, 28 levels
Spectral Nudging Yes Yes No No No No Yes
Lateral Boundary Treatment cos^2 relaxation with 1h-24h time scale 10 semi-lag departure points 10 semi-lag departure points Tanh functional form of weights 8 point Davies cosine-based relaxation nudging with exponential weights linear relaxation
Original
Grid Size
200 x 180 (0.44°)
380 x 340 (0.22°)
212 x 200 (0.44°)
380 x 340 (0.22°)
212 x 200 (0.44°)
380 x 360 (0.22°)
695 x 680 (0.11°)
182 x 152 186 x 150 189 x 161 (50-km)
381 x 325 (25-km)
159 x 151 (50-km)
318 x 302 (25-km)
Sponge Zone
Depth
4.4 degrees (all resolutions) 10-point Davies blending 10-point Davies blending 10 points 10 points 12 points (50-km)
24 points (25-km)
5 points (50-km)
10 points (25-km)
Spin-up Period 1 year None ERA-driven simulations start 1958 1 year 1 year 1 year for ERA-driven simulations 1 to 2.5 years depending on simulation
Length of Timestep 1200s (0.44°)
600s (0.22°)
1200s (0.44°)
600s (0.22°)
1200s (0.44°)
600s (0.22°)
300s (0.11°)
600 seconds 1200 seconds 100s (50-km)
50s (25-km)
300s (50-km)
150s (25-km)
tasmin / tasmax Calculation timestep timestep timestep timestep timestep land surface timestep 3-hourly
Longwave Radiation Scheme Correlated-k distribution and McICA for clouds Li and Barker correlated-k radiation Li and Barker correlated-k radiation Morcrette (1984) Sass et al. (1994) Kiehl et al (1996) RRTM
Shortwave
Radiation
Scheme
Correlated-k distribution and McICA for clouds Li and Barker correlated-k radiation Li and Barker correlated-k radiation Fouquart and Bonnel (1980) Sass et al. (1994) Kiehl et al (1996) Goddard (ra_sw_physics=2)
Uniform Aerosols prognostic bulk aerosols ozone ozone yes yes no ozone+trace gases, no aerosols
Modeler J. Scinocca S. Biner K. Winger F. Boberg
O. Christensen
G. Nikulin R. Arritt
M. Bukovsky
M. Bukovsky
C. Castro
H-I Chang
Institution CCCma Ouranos UQAM DMI SMHI Iowa State
NCAR
NCAR
U Arizona
Reference Scinocca et al (2015), J. Clim. 29, p.17 Zadra et al., 2008; Martynov et al. 2013; Šeparović et al. 2013 Zadra et al., 2008; Martynov et al. 2013; Šeparović et al. 2013 DMI report 06-17 Samuelsson et al. (2011), Tellus A 63.1; SMHI-RCA4 setup description Giorgi et al (2012) Climate Research Skamarock et al (2008) NCAR Tech Note