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Arctic and Antarctic sea ice simulated by CNRM-CM5 coupled global climate model

Arctic and Antarctic sea ice simulated by CNRM-CM5 coupled global climate model. David Salas y Mélia(1) , M. Chevallier (1), A. Alias(1), S. Belamari(1), C. Cassou(2), B. Decharme(1), H. Douville(1), E. Maisonnave(2), D. Saint-Martin (1), E.Sanchez(2),

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Arctic and Antarctic sea ice simulated by CNRM-CM5 coupled global climate model

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  1. Arctic and Antarctic sea ice simulated by CNRM-CM5 coupled global climate model David Salas y Mélia(1), M. Chevallier (1), A. Alias(1), S. Belamari(1), C. Cassou(2), B. Decharme(1), H. Douville(1), E. Maisonnave(2), D. Saint-Martin (1), E.Sanchez(2), S. Sénési(1), S. Tyteca (1), S. Valcke(2) et A. Voldoire (1) CNRM-GAME, (2) Cerfacs CNRM-GAME / Mercator, 14 June 2010

  2. Objectives • Update CNRM-CM3 (one of the IPCC-AR4 models) • Participation to CMIP5 (Coupled Model Intercomparison Project phase 5), through long term (‘centennial) and near term (decadal hindcast and forecast) simulations • A contribution to European projects (Combine, Euclipse) and national projects • Provide surface and lateral boundary conditions to regional models (CORDEX) • Use of CNRM-CM5 in seasonal prediction mode

  3. External forcings Aerosols Greenhouse gases Solar irradiance CNRM-CM5 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. The main changes in CNRM-CM • ARPEGE-Climat v5.2 T127 L31 (~1.4° horizontal resolution) • RRTM new radiation scheme • Re-calibration of the climate impact of atmospheric aérosols (tropospheric + stratospheric volcanic) • Water vapour conservation by the dynamics is now imposed • Implementation of SURFEX 5 in ARPEGE-Climat (hence CNRM-CM5 !) • 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. 2009 version) • Free surface • Revised TKE scheme • Sea Ice : Gelato v5 • New thermodynamics • Most of the code is now parallel

  5. A modelling effort on sea ice : Gelato • History • The development of Gelato was initiated in 1996 (a multi-category model) • Dynamics + redistribution by rafting and ridging(1998) • EVP (2000) • New features • Prognostic salinity • Salt uptake : follows Cox and Weeks (1988) • Desalination processes adapted from Vancoppenolle et al., O. Modelling (2009) • Enthalpy model • H = H(T,S) and Cp=Cp(T,S) • Vertical Heat Diffusion (VHD) • Ice thermal conductivity k is a function of T,S (Pringle et al., 2007) • An update of T through the VHD implies that Cp and k are updated in turn  iterative solving of the vertical heat diffusion scheme • Revised snow albedo (adapted from Curry et al. (2001) • New tracers can now easily be implemented (ice age recently implemented)

  6. 1) Gelato in forced model : Forcing data • Atmospheric fields form the DRAKKAR Forcing Set 4 (DFS4) • Brodeau et al (2010) • Surface turbulent fluxes over the oceans are calculated using CORE bulk formulae • Before 1984 (resp. 1979) radiative fields (resp. precipitation) are set to their 1984-2004 (resp 1979-2004) climatologies

  7. 1) Forced mode: Mean sea-ice concentration March and September 1984-2001 simulated mean ice concentration Black line is HadISST observed ice-edge

  8. 1) Forced mode: Mean sea-ice thickness March and September 1984-2001 simulated mean ice thichness (in m)

  9. 1) Forced mode: Mean seasonal cycle 106 km2 months

  10. 1) Forced mode: Fram Strait ice export 106 km2 Arctic sea-ice volume: Winter mean: 22 103 km3 Summer mean: 6 103 km3 Observations 1978-2004(Kwok et al, 2004): 0.9 106 km2 /yr 2.2 103 km3/yr Simulated Fram Strait ice export: Areal annual export: 1.1 106 km2 /yr(max: 1.5 106 km2 in 1995)Volume annual export: 1.3 103 km3/yr(max: 1.9 103 km3 in 1995)

  11. 1) Forced mode: a bias in the solar forcing field ? Difference in incoming solar flux (DFS4 – ERA-Interim )

  12. 1) Forced mode: a melt ponds parameterization Simulated Albedo 1980-1985 mean JJA sea-ice albedo simulated by GELATOleft: current parameterization, middle: new melt pond parameterizationright: difference ponds - no_ponds

  13. 1) Forced mode: a melt ponds parameterization Ice concentration response 1980-1985 September mean ice concentration simulated by GELATO - left: current parameterization, middle: new melt pond parameterization - right: difference ponds - no_ponds

  14. 2) Experiments in coupled mode (CNRM-CM5)

  15. 1990 simulation CNRM-CM5 / CMIP5 / IPCC AR5 (2010) SPEA ann. 20-49 (Turb. Fluxes O-A Ecume) Annual mean surface Temperature bias (°C) - ocean: simulated SST – HadISST 1970-1999 - atm: simulated T2m – CRU 1970-1999 rms=2.17 mean=-1.40 CNRM-CM3.1 / CMIP3 / IPCC AR4 (2004) CNRM-CM3.3 / FP6 ENSEMBLES (2008) rms=2.31 mean=-1.46 rms=2.24 mean=-0.20

  16. 1990 simulation Sea Ice extent (>15%), million km2 SPEA ann. 20-49 HadISST (observations 1970-1999) CNRM-CM5 / CMIP5 / IPCC-AR5 (2010) ARCTIC

  17. 1990 simulation Sea Ice concentration SEPTEMBER ( [0-1] ) SPEA ann. 20-49 HadISST (observations 1970-1999) CNRM-CM5 / CMIP5 / IPCC-AR5 (2010) CNRM-CM3.1 / CMIP3 / IPCC AR4 (2004) CNRM-CM3.3 / FP6 ENSEMBLES (2008)

  18. 1990 simulation Sea Ice concentration MARCH ( [0-1] ) SPEA ann. 20-49 HadISST (observations 1970-1999) CNRM-CM5 / CMIP5 / IPCC-AR5 (2010) CNRM-CM3.1 / CMIP3 / IPCC AR4 (2004) CNRM-CM3.3 / FP6 ENSEMBLES (2008)

  19. 1990 simulation Sea Ice extent (>15%), million km2 SPEA ann. 20-49 HadISST (observations 1970-1999) CNRM-CM5 / CMIP5 / IPCC-AR5 (2010) ANTARCTIC

  20. 1990 simulation Sea Ice concentration ( [0-1] ) SPEA ann. 20-49 CNRM-CM3.3 - HadISST (1970-1999) CNRM-CM5 - HadISST (1970-1999) CNRM-CM3.3 - HadISST (1970-1999) CNRM-CM5 - HadISST (1970-1999)

  21. 1990 simulation Sea Ice salinity ( psu ) SPEA ann. 20-49 March September

  22. Quelques pistes de collaboration CNRM-GAME / Mercator ( + IPSL, UCL) • Modèle forcé: problème radiatif probable dans les hautes latitudes dans les forçages Drakkar (DFS4) • Choix d’une nouvelle dynamique pour Gelato : granulaire ? (coll. B. Tremblay, Mc Gill, Canada); collaboration UCL ? Partage de librairies au sein de NEMO ? • Travail en commun au sujet des flux turbulents sur glace ? • Augmentation de la résolution de NEMO-Gelato en mode climat (eddy resolving 0,25° ?) • Prospective CSOA: réunion concernant l’Arctique les 6 et 7 juillet

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