Adaptive Grids in Climate Modeling: Dynamical Core Tests

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Adaptive Grids in Climate Modeling Dynamical
Core Tests

• Christiane Jablonowski,
• M. Herzog, R. Oehmke,
• J. E. Penner, Q. Stout, B. van Leer
• University of Michigan, Ann Arbor, MI
• in collaboration with NASA/GSFC and NCAR

AGU Dec 2003
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Adaptive Grids in Climate Modeling

• First dynamically adaptive 3D dynamical core on
  the sphere
• based on NASA/NCARs finite volume hydrostatic
  dynamical core
• Block data structure with AMR library support
• First dynamically adaptive 2D shallow water model
  on the sphere
• Shallow water model is 1-level version of
  thedynamical core

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Overview of results Highlights

• 2D shallow water tests
• First glimpse Track the features of interest
• Advection experiments
• Advection with a reduced grid
• Static refinements in regions of interest
• Dynamic refinements Flow over a mountain
• 3D dynamical core tests
• Static refinements along the storm track
• Dynamic refinements with vorticity criterion

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First glimpse Adaptations at work
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Dynamic adaptations and the reduced grid

• No noise or distortions
• accurate transport

2 reductions
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2D Static adaptations Region of interest

• Smooth flow in regimes with strong gradients

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2D Static adaptations Closer look

• Smooth wind field
• No noise or distortions at the fine-coarse grid
  interface

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2D Dynamic adaptations
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Baroclinic waves in the 3D regime

• Jablonowski-Williamson baroclinic wave test case
  for dyn. cores
• Coarse resolution does not resolve the wave
  train

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Static adaptations in 3D

• 1 Refinement along the storm track improves the
  simulation

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Static adaptations in 3D

• 2 Refinements along the storm track capture the
  wave accurately

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Dynamic adaptations in 3D

• Polvani-Scott baroclinic wave test case
• Refinements are guided by relative vorticity
  threshold

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Conclusions

• Static and dynamic refinements on the sphere
  work
• AMR is a current research topic for the
  atmospheric sciences
• Future outlook
• Static and dynamic adaptations are a viable
  option for short-term weather predictions
• track storms as they appear
• focus on forecast region of interest replace
  nested grids
• Static adaptations are feasible for long-term
  climate studies
• refine mountainous terrain, reinitialize
  orography
• Future steps Add physics package, build a
  full GCM