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Which variables are those options(conv_tr* and chem_conv_tr) related to?

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cxyiyh

Member
Hi, friends,
Because of the increased cloud water content, the aqueous phase chemistry is accelerated, which is also part of the ACI.
And I want to know how to handle some options of conv_tr_aqchem or conv_tr_wetscav?Which variables are those options(conv_tr* and chem_conv_tr) related to?


conv_tr_aqchem
= 0 subgrid convective aqueous chemistry turned off in the simulation(if no parameterization is used or for debugging)
= 1 subgrid convective aqueous chemistry turned on in the simulation(default). Currently connected to “MADE” modal aerosol options.

conv_tr_wetscav
= 0 subgrid convective wet scavenging turned off in the simulation (if no parameterization is used or for debugging)
= 1 subgrid convective wet scavenging turned on in the simulation (default)

chem_conv_tr
= 0 subgrid convective transport turned off in the simulation (if no parameterization is used or for debugging)
= 1 subgrid convective transport turned on in the simulation (default)
What is process of subgrid convective?How do I know if I should turn them on?
yours,
cxyiyh
 
Hi all,

These options are related to interactions between aerosols and the cumulus parameterization; i.e., in WRF, clouds/precipitation have both a resolved and unresolved/parameterized component - the latter being the cumulus parameterization.

When chem_conv_tr = 1, you are telling the model to to TRansport CHEMical species in the CONVective parameterization (i.e., the cumulus scheme).

When conv_tr_wetscav = 1, you are telling the model to perform WET SCAVenging of chemical species within the CONVective parameterization

When conv_tr_aqchem = 1, you are telling the model to perform aqueous chemistry within the CONVective parameterization

Note that prior to WRF v4.3, the convective transport of chemical species was performed separately from the transport of other scalars. The chemical transport was performed by the GD cumulus scheme no matter which cumulus option you are using. In v4.3, a user supplied new code (https://github.com/wrf-model/WRF/pull/1354) that couples the convective transport, wet scavenging, and aqueous chemistry to the GF cumulus scheme, so that when the GF scheme is chosen in the namelist, chemical species and other scalars are transported consistently.

Please let me know if you have further questions.

Jordan
 
Hi Jordan,

Thank you for your detailed explanation!
I see. So they only work with GF cumulus option.

Thank you.

Lily
 
Hi Lily,

Not quite. All of these options work with any cumulus scheme that is chosen.

Prior to v4.3, the convective transport was done using the GD cumulus algorithm inside the chemistry code no matter what cumulus option you chose (i.e., one could run with any cumulus option, but the chemistry will be transported using the GD scheme, so there will be inconsistencies). After v4.4, if you use the GF scheme, the convective transport, aq, and wetscav is done inside the GF scheme in physics, getting rid of those inconsistencies. But if you use another cumulus options, the code will perform as prior to 4.3 (i.e., chemistry transported with GD, other scalars transported with chosen cumulus scheme).

Jordan
 
Hi Jordan,

Thank you for your further explanation!
Actually, I am trying to use one namelist.input from previous group memeber which used MSKF and turn off these three options in WRF/Chem3.9.1, I am not sure why they turned off them. And now I want to test GF, I am considering if I should turn on them for retrospective simulation.

Thank you.

Lily
 
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