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WACCM3 Basic FAQ

andrew

Member
Q: What computer architectures does WACCM3 run on?
A: WACCM3 runs on NCAR's IBM POWER5 supercomputers (bluevista and bluefire). Support is not provided for other computing environments.

Q: How much memory does WACCM3 require?
A: This depends on resolution. At 4x5 degrees horizontal resolution WACCM3 requires nearly 2 GB of memory.

Q: How do I run WACCM3?
A: Scripts for running WACCM3 on the NCAR supercomputers are available as part of the WACCM3.1.9 release code on the community data portal (http://cdp.ucar.edu, look at models, WACCM, source code distribution).

Q: How long does one year of simulation typically take?
A: This depends on resolution. On 128 bluefire processors one year of simulation takes about 6.5 wallclock hours at 1.9 x 2.5 degrees horizontal resolution.

Q: What is the computational cost of running WACCM3?
A: One year of simulation at 1.9 x 2.5 degrees costs about 1150 GAUs under 'regular' charging.

Q: What types of runs can I do with WACCM3?
A: Both time-slice and transient simulations can be performed with WACCM3. Refer to the
namelist variable definitions, and sample namelists for an example of specify each type of run.
(http://cdp.ucar.edu, look at models, WACCM, source code distribution, scripts)

Q: I try to run WACCM3 and it core dumps at the first timestep. What should I do now?
A: Make sure you can first run the sample scripts. Verify you have followed the instructions here and can reproduce the sample output files (available at http://cdp.ucar.edu, look at models, WACCM, source code distribution, scripts). If you are able to these scripts without error, it is likely there is an error in one of the input file or namelist file. You may also want to check the
bulletin board to see if your problem has been encountered by another user.

Q: How much disk space does WACCM3 output require?
A: This depends on the frequency and number of output fields. One 3-D variable at 1.9x2.5 degrees resolution requires 4 MB of storage. A typical monthly mean file at the same resolution requires 600 MB of storage per month.

Q: How do I modify the frequency and quantity of the output?
A: This is done in the same way as CAM3, via the namelist file. Refer to CAM3 documentation (http://www.ccsm.ucar.edu/models/atm-cam/) and the sample namelist files (http://cdp.ucar.edu, look at models, WACCM, source code distribution, scripts).

Q: How do I view WACCM3 output. A: Any visualization software that can read netcdf data can read WACCM3 output.

About the model

Q: What is the horizontal resolution of WACCM3?
A: The current release of WACCM3 has input datasets for 4x5 and 1.9x2.5 degrees (latitude x longitude). These are the only resolutions supported.

Q: What is the vertical resolution?
A: There are 66 vertical levels. Resolution varies with height from about 1km in the troposphere to 2 levels per scale height in the mesosphere and lower thermosphere. The levels are fixed in the current release, and extend from the surface to ~140 km.

Q: What chemical species are calculated in WACCM3?
A: WACCM3 calculates the concentrations of 57 neutrals and ions. The chemistry package is described in detail elsewhere (See Kinnison and Garcia recent papers)

Q: Can I modify the chemistry?
A: No. Due to the complexity of the chemical solver and the need to calculate photolysis look-up tables, the chemistry in WACCM3 is fixed.
 
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