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C1 and C2 for boundary variables

C

Chetan

Member
Hi everyone,
Wrf uses the C1 and C2 values to calculate boundary values according to this post Definitions of _BTXE and _BXE in wrfbdy output
For example, for qv : qv(i,k,j)*C1(k) * ( mub(i,j) + mu(i,j) ) + C2(k).

I would be grateful if someone could explain the following questions:
How does WRF calculate C1 and C2 in this context?
Does the file wrfbdy_d01 contain C1 and C2?
Can we calculate it manually? If so, how can this be done?

Thank you very much for your time and consideration.

Best,
Chetan
 
Thank you very much @kwerner for your response. I found wrf itself calculates these constants and can be found in wrfout, however, I am it is unclear how it is calculated in wrf.
 
So it looks like C1 and C2 are actually c1h and c2h. Look at the Registry/registry.hyb_coord file, which gives the definition, which includes a simple equation for those variables. You can also do a case-insensitive search for those variables throughout the WRF code. You'll probably want to look at only the *.F files, but you may be able to find some specific calculations within the code - of course, those may then lead you down more paths to find the variables used to calculate them.
 
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