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metno / emep-ctm

Open Source EMEP/MSC-W model
GNU General Public License v3.0
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Understanding model run on a smaller domain #47

Closed JessMBemep closed 5 years ago

JessMBemep commented 5 years ago

Hi, I whish to run the model on a smaller domain than the full regional domain. I understood that it can be set by using RUNDOMAIN variable in the Model Constants_config namelist. Although the model run well, I am wondering about the behaviour of the model for this kind of simulation, mainly the setting of boundary conditions.

  1. Actually, I did not find the module GlobalBCs_ml.f90 within the codes' folder that I downloded; besides, I do not realize what are the inputs (datasets) that the model use for setting boundary conditions.
  2. How the model manages bondary conditions for simulation of smaller domains? Has the model any specific interpolation routine for setting boundary conditions?
  3. In case I want to use a nesting run, could a base-run simulation (i.e. the full regional domain) be used as boundary for the smaller domains, it would be advisable?

Many thanks in advance

gitpeterwind commented 5 years ago

Hi, There are default Boundary and Initial conditions. Generally low background values (smoothly distributed). These can cover any domain. They are defined in BoundaryConditions_ml.f90 . A nested run can be advantageous if you have for example fine scale data in a limited region, but still want to include long range transport to this region. If you use the same resolutions in the nested runs, you should not see much differences. It can still be useful if you want to do many runs in the smaller domain with the same long range domain.

gitpeterwind commented 5 years ago

See also section 10 for an explanation of the actual values set at BC: https://www.atmos-chem-phys.net/12/7825/2012/acp-12-7825-2012.pdf

JessMBemep commented 5 years ago

many thanks!

avaldebe commented 5 years ago

Hi @JessMBemep

Looks like your question was answered, so I will close the issue. Just re-open it if that was not the case.

If you have more questions, please do not hesitate to open a new issue.