Coupled & Ocean 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)

Momentum, Energy, H 2 O, CO 2 Land HD JSBACH Atmosphere ECHAM5/6 Solar variations Volcanic aerosol CO 2 emissions Natural forcing Anthropogenic forcing Land use change CH 4, N 2 O, CFC conc. 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 The MPI-M Earth System Model

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

dipole global application: GR3.0 and GR1.5 dipole regional application MPIOM- grid set-ups dipole grid

Tri-polar, quasi-homogeneous 1°, 0.4°, 0.1° tripole grid set-up

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

Griffies et al., 2009 MPIOM: TP04 Resolution matters (sometimes…)

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 years of data!)

HadCRUT2v CRUTEM2v Expt. 1Expt. 2 Expt. 4Expt. 2 Expt. 3 anomalies w.r.t mean Simulation captures warming trend over 19th/20th century Observed multidecadal variations partly due to internal variability Northern Hemisphere temperatures: the instrumental period

Northern Hemisphere temperatures: the last 1200 years 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% Background shading: overlay of reconstructions (after IPCC, 2007)

Simulation of CO 2 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 NCEPGECCO Gain in skill

SAT hind minus 20C COR skill for yr6-10 NCEP GECCO Gain in skill

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…) MPIOM at high resolution (0.1°)

a snapshot of horizontal velocity speed at 57 m [m/s]

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) ECHAM6/MPIOM in CMIP5

CO 2 CONCENTRATION2423 control 1850C C+2*T13*156 RCP C+2*T13*95 RCP T1200 RCP C+23*95 RCP T2200 RCP T1+23*95 RCP T2200 CMIP5 ECHAM6/MPIOM-HR C: CORE, T1: Tier1, T2: Tier 2

CO 2 Emission1003 Control C-cycleC C-cycleC156 RCP C-c.C decoupledT1156 RCP dec.T rad. onlyT2156 RCP rad.T295 CMIP5 ECHAM6/MPIOM-HR C: CORE, T1: Tier1, T2: Tier 2

Initialized decadal2700 Initialized, 10 yr30*C+70*T1100*10 Initialized, 30 yr6*C+14*T120*30 Initialized - volcanoe15*T1+3550*10 Initialized + volcanoe3*T1+710*10 CMIP5 ECHAM6/MPIOM-HR C: CORE, T1: Tier1, T2: Tier 2

Paleo: PMIP36000 control mid holocene2000 control LGM2000 Control Millennium Mid holoceneT1100 LGMT1100 Last MillenniumT21200 Total7400 CMIP5 ECHAM6/MPIOM-LR C: CORE, T1: Tier1, T2: Tier 2

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, non- boussinesq (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 A representation of the frazil- pancake 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 The new sea-ice model will include:

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: MPI-M's Next Generation Climate Model

ICON Development Branches 2D shallow water 3D hydrostatic atmos. dynamical core ICOHAM as successor of ECHAM 3D non-hydrostatic numerics 3D hydrostatic ocean + ECHAM physics

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 one external modea few fast vertical modes, vertical mode decomposition every time step Elliptic problem for... operators: divergence, vorticity, gradient elliptic solver, time stepping Commons Equations z levelshybrid terrain followingVertical coordinate Hydrostatic OceanHydrostatic AtmosphereModel

 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  1 st 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

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 ICON Ocean model: further development