Coupled & Ocean Modelling
@ MPI-M
Johann Jungclaus
Max-Planck-Institut für Meteorologie
Ocean model development at MPI-M has
presently two foci:
Maintain and improve the Max Planck Institute
Ocean Model (MPIOM) as part of the MPI-M Earth
System Model (E. Maier-Reimer, H.Haak, J.
Jungclaus, J-S. v. Storch)
Develop a new ocean model in co-operation with
new atmosphere model ICON (P. Korn, S. Lorenz,
PhD students)
The MPI-M Earth System Model
Anthropogenic forcing
Natural forcing
CH4, N2O, CFC conc.
Volcanic aerosol
CO2 emissions
Solar variations
Land use change
Atmosphere
ECHAM5/6
Momentum, Energy,
H2O, CO2
Land
HD
JSBACH
Ocean
MPIOM
HAMOCC
The MPI-M Earth System Model
• ECHam5/6 (Roeckner et al.,
2003), interactive runoff and
glacier calving scheme.
• Land surface JSBACH (Raddatz
et al., 2007), Dynamic Vegetation
(Brovkin et al., 2009)
• New Radiation
• Resolution: T31L19, T63L47,
T127/L95, …..
• OASIS 3.0 coupler
• MPIOM
MPIOM
• MPIOM (Marsland et al., 2003),
• C-Grid, z-level, partial cells, BBL parameterization
• Isopycnal diffusion, GM (Gent et al., 1995; Griffies et al.,
1998)
• Vertical mixing: PP and mixed layer wind mixing
• Hibler-type sea ice model incl. snow and fractional ice cover
• Conformal mapping grid: dipole or tripole
• Ocean biogeochemistry module HAMOCC5 (Wetzel et al.,
2007)
MPIOM- grid set-ups
dipole grid
dipole global
application:
GR3.0 and GR1.5
dipole regional application
tripole grid set-up
Tri-polar, quasi-homogeneous
1°, 0.4°, 0.1°
Paleo applications
PETM (55 Ma)
PhD thesis M. Heinemann
dipole grid
Miocene (15 Ma)
PhD thesis M. Krapp
tripole grid
Resolution matters
Griffies et al., 2009
MPIOM: TP04
Resolution matters (sometimes…)
Griffies et al., 2009
MPIOM: TP04
Applications
• long (and, or many) integrations with
effective low-resolution ESM (T31/GR3)
• Ensemble simulations of the Last
Millennium
• Multi-millennia transient experiments (e.g.
Holocene)
• Sensitivity experiments in paleo
environment (e.g., PETM, Miocene)
Example: Last Millennium
• first ensemble simulations over the last
1200 years using comprehensive ESM
including interactive carbon cycle. (In total,
almost 20000 years of data!)
Northern Hemisphere temperatures:
the instrumental period
CRUTEM2v
Expt. 1
Expt. 2
Expt. 4
HadCRUT2v
Expt. 3
Expt. 2
anomalies w.r.t. 1961-1991 mean
•Simulation captures warming trend over 19th/20th century
•Observed multidecadal variations partly due to internal
variability
Northern Hemisphere temperatures:
the last 1200 years
Background shading: overlay of reconstructions (after IPCC, 2007)
solid: 5 full forcing expts. (Krivova solar 0.1%)
dashed: 3 full forcing expts. (Bard solar 0.25%)
• Range of variability consistent with observations, but LIA
cooling less pronounced than in reconstruction for 0.1%
Simulation of CO2 evolution
Solid lines: full forcing ensemble E1 (Krivova solar, 0.1%)
dashed lines: full forcing ensemble E2 (Bard solar, 0.25%)
Grey shading: Overlap of reconstructions (C. Reick)
Applications
• Decadal prediction and ocean initialization
• No data assimilation for MPIOM available, but
benefit from Detlef Stammer‘s GECCO work in
the neighborhood
• Presently testing several „assimilation“
techniques in AR4 set-up (ECHAM5 T63L31
MPIOM GR1.5L40) : SST (Keenlyside et al.,
2008),
• GECCO (Pohlmann et al., 2009)
• Forced (NCEP) MPIOM runs (Matei et al., in
prep.)
SAT hind minus 20C COR skill for lead time 1yr
NCEP
Gain in skill
GECCO
SAT hind minus 20C COR skill for yr6-10
NCEP
Gain in skill
GECCO
MPIOM at high resolution (0.1°)
STORM-project (J.S. v. Storch)
- using IPCC AR5 model system (ECHAM6/MPIOM-TP)
- long climate change simulations (i.e., 20 century run + 21
century run with RCP4.5 forcing)
- horizontal resolution in the ocean: ~ 1/10 degree (10km)
- horizontal resolution in the atmosphere: ~ 50 km
Scientific foci (among others):
- Climate sensitive & dependence of climate sensitive on
resolution (e.g. whether and to what extent will climate
projections change due to enhanced resolution)
- Impact studies (e.g. changes of extreme value statistics…)
a snapshot of horizontal velocity speed at 57 m [m/s]
ECHAM6/MPIOM in CMIP5
• MPI-M will run CMIP5 experiments 20th
century, projections, and decadal forecast
using ECHAM6 T127/L95 MPIOM 0.4/L80
„HR“
• Paleo and historic (last millennium) will be
run at T63L47 (ECHAM6) and 1°L40
(MPIOM) „LR“
• Expts with interactive chemistry will be run
at „LR“ at FZ Jülich (M. Schultz)
CMIP5 ECHAM6/MPIOM-HR
CO2 CONCENTRATION
2423
control 1850
C
500
1850-2005
C+2*T1
3*156
RCP4.5 2006-2100
C+2*T1
3*95
RCP4.5 2101-2300
T1
RCP8.5 2006-2100
C+2
RCP8.5 2101-2300
T2
RCP2.6 2006-2100
T1+2
RCP2.6 2101-2300
T2
200
3*95
200
3*95
200
C: CORE, T1: Tier1, T2: Tier 2
CMIP5 ECHAM6/MPIOM-HR
CO2 Emission
1003
Control C-cycle
C
250
1850-2005 C-cycle
C
156
RCP8.5 2006-2100 C-c.
C
95
1850-2005 decoupled
T1
156
RCP8.5 2006-2100 dec.
T1
95
1850-2005 rad. only
T2
156
RCP8.5 2006-2100 rad.
T2
95
C: CORE, T1: Tier1, T2: Tier 2
CMIP5 ECHAM6/MPIOM-HR
Initialized decadal
2700
Initialized, 10 yr
30*C+70*T1
100*10
Initialized, 30 yr
6*C+14*T1
20*30
Initialized - volcanoe
15*T1+35
50*10
Initialized + volcanoe
3*T1+7
10*10
C: CORE, T1: Tier1, T2: Tier 2
CMIP5 ECHAM6/MPIOM-LR
Paleo: PMIP3
6000
control mid holocene
2000
control LGM
2000
Control Millennium
2000
1400
Mid holocene
T1
100
LGM
T1
100
Last Millennium
T2
1200
Total
C: CORE, T1: Tier1, T2: Tier 2
7400
Working fields
• Tides (E. Maier-Reimer, M. Müller)
• New sea ice model (D. Notz)
• Vertical mixing (E. Exarchou, J. v. Storch,
JHJ)
• Adaptation for high resolution (0.1° or
higher) models (non-hydrostatic, nonboussinesq (E. Maier-Reimer))
Tides
• Ephemeridic module of Thomas et al. [2001] implemented
in MPIOM
• Analytical ephemerides for the sun and moon
calculated with sufficient accuracy for tidal applications
(~0.1‘ for the sun, 1-2‘ for the moon) [van Flandern and
Plukkinen, 1998]
• Real-time forcing of complete lunisolar tidal potential
New sea-ice model
The new sea-ice model will include:
• A representation of the frazilpancake cycle and the
associated brine release
• An improved representation
of salt fluxes from ice during
growth and decay
• Multi-layer, multi-category
sea-ice thermodynamics
• Improved albedo scheme
(Pedersen et al., 2009)
• Dynamics on triangular grid
for ICON is planned
ICON: MPI-M's Next Generation Climate Model
• Coupled atmosphere & ocean model on identical grid type
• Icosahedral grid: unstructured grid that avoids problems of
lat/lon grids: pole singularity, non-uniformity of grid cells
• Collaboration with German Weather Service (DWD)
• Includes data assimilation
• Joint pool of physics packages
• From short & local to long & global time-space scales weather
and climate prediction
•
Local model refinement: horizontal & vertical
• regional/local modelling
• covering hydrostatic & nonhydrostatic regime
ICON Development Branches
2D shallow water
3D hydrostatic
atmos. dynamical
core
3D non-hydrostatic
numerics
+ ECHAM physics
ICOHAM
as successor of
ECHAM
3D hydrostatic
ocean
The ICON Grid
Concept of patches
 for refinement
 for domain decomposition
Unstructured grid
 minimize distance between neighbors
in memory
 only relationships between neighbors
are stored: no traditional array data
structure
Ocean model versus Atmosphere model
Model
Hydrostatic Atmosphere
Hydrostatic Ocean
Vertical coordinate
hybrid terrain following
z levels
Elliptic problem for...
a few fast vertical modes, vertical
mode decomposition every time
step
one external mode
Equations
Commons
operators: divergence, vorticity, gradient
elliptic solver, time stepping
ICON Ocean model
 Primitive equation model with a free surface
Discretization of vector-invariant form of momentum equation
 Spatial Discretization: C-type staggering
 Normal velocity: at triangle edges
 Temperature & salinity: at triangle centers
 Free surface elevation: at triangle centers
Temporal Discretization: semi-implicit two-timelevel scheme
ICON Ocean model
Dynamics
 1st version of dynamical core implemented and tested
Physics (work-in-progress)
 Forcing
Momentum/heat/fresh-water fluxes (CORE-project)
Bulk formulas
 Parametrizations
Vertical mixing, convection
 Grid-dependent physics (GM) requires substantial development
ICON Ocean model: further development
Ocean data assimilation/state estimation
using adjoint method
 Adjoint model via adjoint compiler
adjoint compiler as integral part of ICON-Ocean model
automatic generation of adjoint code
 Strategy
ICON-Ocean development parallel with adjoint development
collaboration with Prof. U. Naumann (RWTH Aachen)
 Current status
adjoint ICON-shallow-water model available