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Using physics schemes individually

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518er2005

518er2005

Member
I want to know how to use the physical schemes individually. Actually, I did go through the MPAS documentation but I am not able to understand how to do that. So if I can get an example of namelist that shows how to use individual physical schemes it will be much helpful.
With regards,
Debashis
 
Just to confirm, are you asking about how you select different physics schemes with an MPAS simulation? For instance run the mesoscale_reference sweet with Kessler microphysics (instead of the default WSM).

Am I understanding your question correctly?
 
Thanks for the reply. Yes this is how i want like i want to use Kain-Fritsch scheme in convection scheme instead of the one in the mesoscale reference suite.
 
Sounds great! That can easily be done. Chapter 6 (Specifically Table 6.3 in the 7.0 User's Guide) will contain references to the namelist variables and possible options you can use in the &physics namelist record. Your confusion might be coming from the fact that these namelist variables are not present under the &physics namelist record of the default namelist.atmosphere file (config_convection_scheme, config_microp_scheme etc.).

This is because some namelist options are hidden by default; this is because the default configurations are well tested. Thus they have to be added in to be used. For your case, using the Kain-Fritsch scheme with the mesoscale_reference suite you can do to the following:

Code: 
&physics
    config_sst_update = false
    config_sstdiurn_update = false
    config_deepsoiltemp_update = false
    config_radtlw_interval = '00:30:00'
    config_radtsw_interval = '00:30:00'
    config_bucket_update = 'none'
    config_physics_suite = 'mesoscale_reference'
    config_convection_scheme = 'cu_kain_fritsch'
/
 
So if I use kain_fritsch scheme the model will only consider only that scheme right? Then what about the scheme which is s already in the mesoscale reference suite, won't it create any error?. Also I got one more query, suppose I don't want use the physics suite inbuilt but want go use schemes of my one choice i.e. completely a new suite, than in this case do we need to off the physics suite or we can just do how you have shown of selecting schemes and run the model?
 
If you use the namelist I listed above, the model will use the Kain Fritsch scheme as the convection scheme instead of the default convection scheme for the mesoscale_reference suite, the New Tiedtke (cu_ntiedtke), and the model will continue to use the other parameterizations in mesoscale reference suite.

If you set config_physics_suite = 'none', all parameterizations will be turned off. You can also add and set all of the individual parameterization namelist variable (config_convection_scheme, config_microp_scheme, etc.) to 'off', which will have the same effect.

If you would like to mix and match parametizations to create your own scheme, the easiest way might be to set config_physics_suite = 'none' and then, using table 6.8 of the 7.0 user's guide select the parametizations that you want.

Does that answer your question?
 
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