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FESOM Toward the COSMOS framework Part I Qiang
Wang Sergey Danilov, Dmitri Sidorenko Ralph
Timmermann, Adriana Huerta-Casas, Silvia Maßmann,
Carmen Böning, Tijana Janjic, Alexey Androssov,
Falk Richter, Jian Zhang, Sandra-Esther
Brunnabend, Verena Haid Sven Harig, Lars Nerger,
Kerstin Fieg Jens Schröter, Wolfgang Hiller AWI,
Bremerhaven, Germany
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Outline

• Model overview
• Validation / Intercomparison
• Examples of application
• Conclusion

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overview
FESOM
I. The ocean component FEOM

• hydrostatic primitive equation OGCM(Danilov et
  al. 2004, Wang et al., 2008, Timmermann et al.,
  2009)
• continuous linear basis functions
• triangles in 2D
• tetrahedra or prism in 3D
• different grid types (z-level shaved cells
  sigma hybrid)

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overview
FESOM
I. The ocean component FEOM

• free surface / non linear free
• GentMcWilliams parameterization
• Laplacian, bi-harm., Smagorinski viscosities
• vertical mixing schemes
• PP, MY2.5,
• f(Ri, Monin-Obukhov-length, TB2004)
• advection schemes
• TG, GLS, FCT
• implicit explicit vertical mixing, adv.,
  Coriolis
• Tides via open boundary (semi-impl. ssh/U)

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Varying resolution with focus on northwestern
Wedell Sea Joao-Marcelo Absy
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overview
FESOM
II. The ice component FESIM

• thermodynamics surface energy balances
  (ParkinsonWashington, 1979)prognostic snow
  layer incl. snow-ice-conversion, but no internal
  heat storage
• advection GLS, FCT

• momentum balance (dynamics)rheologies 1.
  viscous-plastic (Hibler, 1979)2.
  elastic-viscous-plastic (HunkeDukowicz, 1997)

III. Coupling of ocean-ice

• formulated on the same surface triangle mesh
• by exchange of momentum, fresh water, and heat
• use ocean surface elevation

Heat flux in a partially ice-covered element
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overview
Benchmark on Power6 (DKRZ) 700 000 mesh nodes
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overview
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validation
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FESOM ice extent and volume
validation
Timmermann et al., 2009
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FESOMice thickness validationvs.Upward
Looking Sonar (Fahrbach)
validation
Timmermann et al., 2009
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Intercomparison
Model intercomparison in Arctic ocean-ice
simulations FESOM, MITgcm, NAOSIM

• AWI-AOMIP examine the ability of Arctic Ocean
  models, understand the strength and weakness of
  the models, obtain useful information on
  improving the models

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Intercomparison
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ice concentration
March mean
September mean
All months mean
FESOM
MITgcm
Observations
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ice thickness
All months mean
FESOM
MITgcm
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Intercomparison
1975-2000 mean ice draft/thickness
Rothrock et al., 2008
FESOM
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Example 1
Overflow dynamics in the West Ross Sea
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Example 1
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Example 1
without tides
Impact on mixing and plume path
Spring tide
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Example 2
East Greenland Coastal Current and Spill Jet
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Example 2
Sect 4
Sect 2
Sect 3
August mean
Sect 1
Kangerdlugssuaq Trough
Sermilik Trough
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3
2
1
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Example 2
Sect 4
Sect 2
Sect 3
February mean
Sect 1
Kangerdlugssuaq Trough
Sermilik Trough
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3
2
1
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Comparison FESOM (diff0, no initial polynya)
AMSR after 36h
Example 3
David Schröder (Uni Trier) / Ralph Timmermann
(AWI)
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Comparison FESOM (diff0, no initial polynya)
AMSR after 50h
David Schröder (Uni Trier) / Ralph Timmermann
(AWI)
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Comparison FESOM (diff0, no initial polynya)
AMSR after 74h
David Schröder (Uni Trier) / Ralph Timmermann
(AWI)
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Conclusion / plan
Toward joining the COSMOS Network
ECHAM5
Vegetation Weathering
Chemistry
Isotope Proxy Models
Ice Sheets Model
OASIS
MPI-OM
FESOM
HAMOCC