Microphysics heating tendency and relationship with cumulus scheme?

[yhwong]

Hello,

I have two question regarding the Microphysics scheme in WRF.

1. I am trying to understand the relationship between the cumulus and the microphysics scheme. As far as I understood, the CU scheme generates the "source" terms which are then handed over to the Microphysics scheme, but how does this work precisely? I understood that the CU scheme detrains cloud and ice at the top. Is this passed on to the MP scheme in the form of Q (i.e. mass variables), or tendencies (i.e. heating and moistening tendencies)?

2. Is there a variable for the heating tendency from the microphysics scheme? i.e. something akin to RTHCUTEN (or RQVCUTEN) from the cumulus scheme. I see that there is "H_DIABATIC" which is the "microphysics latent heating" and "qv_diabatic" which is the "microphysics QV tendency", but they are not actually terms outputted by the microphysics schemes, so I am not sure if they are the ones I am looking for. I would like to compare the heating rates from Cumulus and Microphysics schemes.

Thanks for your help and pointers!

 

[Ming Chen]

In WRF, the cumulus, radiation, PBL etc. schemes are activated before microphysics is called. Basic elements like U, V, Theta, QV etc. are updated and serve as input to microphysics. That is to say, the tendencies from cumulus scheme are to directly passed into microphysics. It is the updated mass variables are input to microphysics. For detailed description of the flowchart, please see https://www2.mmm.ucar.edu/wrf/users/docs/technote/v4_technote.pdf

"H_DIABATIC" and "qv_diabatic" are diagnostic variables from microphysics. They should be the variables you are looking for.