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Current state of ECHAM5/NEMO coupled model. Wonsun Park, Noel Keenlyside, Mojib Latif (IFM-GEOMAR) René Redler ( NEC C&C Research Laboratories ) DRAKKAR meeting 25-26 January 2007, Grenoble, France. Outline. Overview of the coupled model 500-yr long simulations Current state
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Current state of ECHAM5/NEMO coupled model Wonsun Park, Noel Keenlyside, Mojib Latif (IFM-GEOMAR) René Redler (NEC C&C Research Laboratories) DRAKKAR meeting 25-26 January 2007, Grenoble, France
Outline • Overview of the coupled model • 500-yr long simulations • Current state • Summary and outlook
Overview of KCM • Kiel Climate Model (KCM): ECHAM5/NEMO coupled model • Component models • AGCM: ECHAM5 (T31L19, T63L31, T106L31), IPCC version • OGCM: NEMO (ORCA2 standard, ORCA05-DRAKKAR configuration), V1_12, NEMO2 • Coupler: OASIS3 or OASIS4 within PRISM
Two 500-yr experiments • Same ORCA2 configuration • NEMO v1_12 • Standard parameters • LIM parameters (hiccrit=0.3,0.6; angvg=-15) • Different ECHAM5 tuning parameters • T31L19 resolution • P53: IPCC cloud scheme and parameters • P57: New cloud scheme (Tompkins, 2002)
Transport (11-yr runavg) 15 13 11 9 7 15 13 11 9 7 MOC 30N P57 New cloud scheme P53 IPCC parameters 160 140 120 100 80 60 160 140 120 100 80 60 Drake passage
TOA Radiation & 2m-temp P53 IPCC parameters P57 New cloud scheme 1.5 1.0 0.5 [W/m2]
SST biases P57 New cloud schemeP53 IPCC parameters
Nino3 spectra 51mn 34mn
Equatorial annual cycles Observation New cloud IPCC parameters
Fraction [%], March Ice area [106 km2] Sea ice Thickness [m], March
angvg=-25 angvg=25 Ice dynamics test • Adopting turning angle of ice drift • Removing island? • Canadian archipelago: hydrological model change , redigitizing? T25 ang=0 no islands T25
Current coupling scheme • NEMO2 • Separate choice of angvg for NH and SH • Preliminary hydrological model tuning in ECHAM5 concerning Canadian archipelago (need further investigation for changing mask in ORCA2?) • All Albedos unified in ECHAM5 (sea ice as well) • Coupling time step: 1x, 4x, 12x/day • Variable exchanged • Ocean to atmosphere (7): SST, sea ice fraction, sea ice thickness, snow thickness, sea ice temperature, zonal-, meridional- ocean velocity • Atmosphere to ocean (11): U-, V- wind stresses on u- and v-grids, total P-E, solid P-E, solar- and non-solar heat flux over water and ice, non-solar heat flux derivative
Ice cover and thickness MOC 30N 13Sv 1 yr 150 Ice area Current run
Ongoing analysis • Tropical variability from ECHAM5/NEMO coupled model (Paper in preparation) • ENSO and MOC relationship on multidecadal scales • Freshwater variability and MOC (with comparison to T42, T63 atmosphere) • Comparison with existing standalone ORCA2 simulations
Summary and outlook • KCM prototype is available for coordinated experiments with standalone NEMO • Two 500-yr long simulations with difference atmosphere configurations: • Stable climate ( <1 W/m2 TOA net radiation) • Importance of atmosphere forcing to ENSO spectra • Still low MOC, cold bias over North Atlantic • YR2007: Constructing higher resolution model • ECHAM5 T63L31/T106L31 coupled to ORCA05 DRAKKAR configuration, OASIS4 • Standalone ECHAM5, NEMO, and coupled model experiments following scientific interests
Mixed layer depth Previous (P57) Current
Meridional Overturning Circulation & Antarctic Circumpolar Current 13Sv MOC P53 9Sv ACC J64 110Sv 95Sv