1 / 24

WRF-CMAQ 2-way coupled system: Part I

WRF-CMAQ 2-way coupled system: Part I. David Wong, Jonathan Pleim, Rohit Mathur, Robert Gilliam, Tanya Otte, Jeffery Young NERL/AMD Frank Binkowski and Aijun Xiu Institute for the Environment, UNC. CMAS 08 October 6-8, 2008. Outline. Current operation scheme Motivation Coupling issues

burt
Download Presentation

WRF-CMAQ 2-way coupled system: Part I

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. WRF-CMAQ 2-way coupled system: Part I David Wong, Jonathan Pleim, Rohit Mathur, Robert Gilliam, Tanya Otte, Jeffery Young NERL/AMD Frank Binkowski and Aijun Xiu Institute for the Environment, UNC CMAS 08 October 6-8, 2008

  2. Outline • Current operation scheme • Motivation • Coupling issues • Design and features • Overall coupled structure • Preliminary results

  3. Current operation scheme

  4. Motivation • Shortcomings of the current way of running met model- MCIP-CMAQ • 32-bit data storage in files • excessive data interpolation • lack of feedback (direct and indirect effect) from CMAQ to the met model

  5. Coupling Issues • Compatibility of met model and CMAQ • model physical aspects • computational aspects • Coupling tool

  6. Coupling Issues: compatibility • Model physical aspects • map projection • coordinate system and grid format • layer structure • time step size • etc

  7. Coupling Issues: compatibility (cont’d) • Computational aspects • domain decomposition • processor and subdomain mapping

  8. Coupling Issues: compatibility (cont’d) • Runtime System Library, RSL • RSL (MM5 and WRF), RSL-Lite (WRF) • RSL-Lite is slightly faster than RSL

  9. Coupling Issues: Tools • Earth System Modeling Framework (ESMF) • Other choices: OpenMI (UK), Model Coupling Toolkit (MCT) (ANL) • M3IO IOAPI Buffered file

  10. Design Strategy • Maintain integrity of WRF and CMAQ models • Minimal code changes: • Keeping the same IOAPI calls • Easy to incorporate new version of WRF • Efficiency: Low coupling overhead • buffered file for data transfer (forward and backward) • buffered file always holds two time steps of data allowing interpolation • Flexibility: easy to add feedback parameters and outputs

  11. Features • Flexible time stepping • CMAQ can be called every WRF timestep or at any user defined multiple • Simple run time switch of feedback • Subdomain tracking • Switch back to disk I/O file for uncoupled mode

  12. WRF-CMAQ system overview WRF CMAQ emission data Solve.F vdiff biogenic emis plume rise surface flux hadv zadv hdiff cldproc chem aero physics drivers radiation microphysics initial conditions dynamics aq_prep met data boundary conditions CMAQ (time, Dt) feedback aerosol data

  13. Example of a call frequency ratio of 4 time line

  14. Preliminary results Offline – 4:1 O3 PM25

  15. Preliminary results (cont’d) 4:1 – 1:1 O3 PM25

  16. Execution time 4:45:02 2:15:23 0:04:21 2:25:18 4:52:07 9:02:52

  17. Preliminary results (cont’d) 4:1 w/o – w/ feedback O3 PM25

  18. Preliminary results (cont’d) w/ feedback 4:1 – 1:1 O3 PM25

  19. Preliminary results (cont’d) w/ feedback 4x8 – 2x4 O3 PM25

  20. Exec. time case w/o feedback w/ feedback 1:1 16:36:04 2x4 8:18:00 4:1 1:1 9:26:11 9:34:28 4x4 4:1 5:13:50 5:20:56 1:1 5:55:10 4x8 3:34:47 4:1 Execution time (cont’d)

  21. To be continued …

More Related