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
Jan 17, 2018
Current state of ECHAM5/NEMO coupled model
Wonsun Park, Noel Keenlyside, Mojib Latif (IFM-GEOMAR)
René Redler (NEC C&C Research Laboratories)
DRAKKAR meeting25-26 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)
MOC 30N
Drake passage
P57 New cloud scheme
P53 IPCC parameters
15
13
11
9
71601401201008060
Transport (11-yr runavg)15
13
11
9
7160140120100
8060
TOA Radiation & 2m-temp
1.5
1.0
0.5[W/m2]
P53 IPCC parameters
P57 New cloud scheme
SST biasesP57 New cloud scheme P53 IPCC parameters
Nino3 spectra 51mn 34mn
Equatorial annual cyclesObservation New cloud IPCC parameters
Sea iceIce area [106 km2]
Fraction [%], March
Thickness [m], March
angvg=-25 angvg=25Ice dynamics test
T25 ang=0 no islands
• Adopting turning angle of ice drift• Removing island?• Canadian archipelago: hydrological model change , redigitizing?
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
Current run
13Sv
1 yr 150
MOC 30N
Ice area
Ice cover and thickness
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
Thanks
Mixed layer depthPrevious (P57) Current
Meridional Overturning Circulation & Antarctic Circumpolar Current
P53
J64
MOC
ACC
9Sv
95Sv
13Sv
110Sv