1. 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

2. Adaptive Grids in Climate Modeling
First dynamically adaptive 3D dynamical core on the sphere
based on NASA/NCAR’s 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 the dynamical core

3. 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

4. First glimpse: Adaptations at work

5. Dynamic adaptations and the reduced grid
No noise or distortions
accurate transport
2 reductions

6. 2D Static adaptations: Region of interest
Smooth flow in regimes with strong gradients

7. 2D Static adaptations: Closer look
Smooth wind field
No noise or distortions at the fine-coarse grid interface

8. 2D Dynamic adaptations

9. Baroclinic waves in the 3D regime
Jablonowski-Williamson baroclinic wave test case for dyn. cores
Coarse resolution does not resolve the wave train

10. Static adaptations in 3D
1 Refinement along the storm track improves the simulation

11. Static adaptations in 3D
2 Refinements along the storm track capture the wave accurately

12. Dynamic adaptations in 3D
Polvani-Scott baroclinic wave test case
Refinements are guided by relative vorticity threshold

13. 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