[Wrf-users] Decouple total theta tendency

[Hein Zelle]

Dear Eowyn Baughman,

> Unofficial<http://forum.wrfforum.com/viewtopic.php?f=37&t=129>
> documentation <http://www.atmos.washington.edu/~scavallo/wrf_thermo.pdf>online
> suggests division by MUT = MU + MUB, but MUT is a total column mass
> (maybe it wasn't in 2008 when those documents were written) whereas the
> theta tendency is 4-dimensional. Currently, I'm dividing RTHRATEN at each
> (lat,lon,eta) point by MUT(lat,lon). Can someone confirm if this is the
> correct approach, or suggest an alternative?

I compute dry, wet and total air mass for each vertical level with 

drymass = (mu + mub) * -1 * dnw
wetmass = drymass * (qcloud + qvapor) 
totalmass = drymass * (1 + qcloud + qvapor + qsnow + qrain)

Units are in Pa, divide by 9.81 to get kg/m^2.

The above may not be 100% correct but it seems to work well enough.


Kind regards,
     Hein Zelle

-- 

Dr. Hein Zelle
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BMT ARGOSS

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