The CNRM-CM5 global climate model: description and basic evaluation

Présentation au sujet: "The CNRM-CM5 global climate model: description and basic evaluation"— Transcription de la présentation:

1 The CNRM-CM5 global climate model: description and basic evaluation
A. Voldoire et al. CNRM-GAME CERFACS

2 The main changes in CNRM-CM between CMIP3 and CMIP5 simulations
ARPEGE-Climat v5.2 T127 L31 (~1.4° horizontal resolution) RRTM new radiation scheme Re-calibration of the climate impact of atmospheric aerosols (tropospheric + stratospheric volcanic) Water conservation is now imposed Implementation of SURFEX 5 in ARPEGE-Climat Surfex is now Météo-France’s standard surface model (used in NWP, meso-scale modelling, climate) + large European consortium New subgrid hydrology, surface tiling Ocean model : NEMO v3.2 1°L42 (nov version) Free surface Revised TKE scheme, tidal mixing Sea Ice : Gelato v5 (same grid as NEMO) (Widely) revised thermodynamics

3 seasonal, decadal & centennial climate prediction
External forcings Aerosols Greenhouse gases Solar irradiance Same model for seasonal, decadal & centennial climate prediction CNRM-CM5.1 Atmosphere ARPEGE-Climat v5.2 T127 (1.4°), 31 levels SURFEX Interface Land surface ISBA 24h 24h OASIS v3 Sea Ice GELATO v5 24h Ocean NEMO v3.2 1°, 42 levels River Routing TRIP 24h

4 Sea level pressure bias w.r.t. ERA40 (1970-1999)
CNRM-CM CNRM-CM5.1 hPa

5 Surface air temp. bias wrt CRU2 & HadSST1 (1970-1999)
CNRM-CM CNRM-CM5.1 °C

6 Precipitation bias wrt GPCP 1979-1999
CNRM-CM CNRM-CM5.1 mm.d-1

7 Evolution CNRM-CM3  CNRM-CM5.1
Variables pronostiques Rayonnement/nuages

8 SST STD ( ) CNRM-CM CNRM-CM5.1 Hadsst1

9 Atlantic MOC CNRM-CM CNRM-CM5.1 obs CM5 NEMO-FOR NEMO-VAR CM3

10 Arctic sea ice thickness 1970-1999
CNRM-CM CNRM-CM5.1 March September m m

11 Antarctic sea ice thickness 1970-1999
CNRM-CM CNRM-CM5 March September m m

12 Drift of the control run
SST linear drift (°C/century) T3D linear drift S3D linear drift (psu/century) Sea level drift (m/century) CNRM-CM3 -0.11 -0.15 +0.006 _ CNRM-CM5.1 +0.01 +0.04 -0.011 -0.21

13 Global mean T2m trend simulated by CNRM-CM5.1
2m air temperature ALL FORCINGS (interpolated to the mask of HadCrut3 observations) + HadCrut3 observations

14 Résumé Résolution accrue
Atmosphère : pas de changement de la physique sauf rayonnement et dynamique Champs pronostiques moins biaisés précipitation/nuages : pas d’amélioration dans CNRM-CM5.1 en attendant la nouvelle physique. Océan : biais SST réduit, MOC Atlantique un peu faible, transports réalistes, dérive en sel non négligeable (+ blue spot) Glace de mer plus réaliste en Arctique (cf Salas-Mélia et al.)