Different spinup times

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neel14
Posts: 100
Joined: Fri Mar 15, 2019 6:52 am

Different spinup times

Post by neel14 » Sun Dec 27, 2020 3:55 pm

Hi,
Is it possible to use different spinup times for meteorology and chemistry? i.e I want to initialize the chemistry after some period of meteorology spinup.

Thanks.

jordanschnell
Posts: 141
Joined: Thu Feb 27, 2020 10:58 pm

Re: Different spinup times

Post by jordanschnell » Mon Dec 28, 2020 6:06 pm

Hi Neeldip,

Try this..

1. Run real.exe with chem_opt=0
2. Run your met-only spinup, and generate a restart file.
3. Run a separate instance of real to generate a wrinput_d01 file with initialized chem arrays.
4. Rename/move&link the wrfinput file to a wrf_chem_input file
5. Run with restart = true, your chem_opt, and chem_in_opt =1.

Alternatively, you could try this.
1 - 3 as above
4. Use ncks to append the chem fields to the restart file (e.g., ncks -v chem_1,chem_2,... wrfinput_d01 wrfrrst_)
5. Run restart = true, and your chem_opt, and chem_in_opt = 0.

Please let me know how this goes. It may be necessary to do the reverse, i.e., put the restart files met data into the wrfinput file.

Jordan

neel14
Posts: 100
Joined: Fri Mar 15, 2019 6:52 am

Re: Different spinup times

Post by neel14 » Fri Jan 01, 2021 6:23 am

Hi Jordan,
I tried the alternate approach. If you compare the variables between the wrfchem input and wrfchem restart file, a lot of variables are missing in the input file.
So if I append the variables from a chem input file to a wrf restart file, I dont think it would work though I haven't got a chance to run.

As for the 1st approach I didn't understand the 4th step.

neeldip
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jordanschnell
Posts: 141
Joined: Thu Feb 27, 2020 10:58 pm

Re: Different spinup times

Post by jordanschnell » Mon Jan 04, 2021 4:40 pm

Hi Neeldip,

The first method is what you should try to use as yes, there are different variables in the restart vs. input file.

As for step 4. If a file named "wrf_chem_input_d01" is in the run directory, with chem_in_opt = 1 and io_form_auxinput12 = 2, the model will use that file to initialize chemistry.

So after you have created the wrfinput_d01 file with chemistry on, simply

ln -s wrfinput_d01 wrf_chem_input_d01

Jordan

neel14
Posts: 100
Joined: Fri Mar 15, 2019 6:52 am

Re: Different spinup times

Post by neel14 » Sun Jan 10, 2021 6:06 am

jordanschnell wrote:
Mon Jan 04, 2021 4:40 pm
Hi Neeldip,

The first method is what you should try to use as yes, there are different variables in the restart vs. input file.

As for step 4. If a file named "wrf_chem_input_d01" is in the run directory, with chem_in_opt = 1 and io_form_auxinput12 = 2, the model will use that file to initialize chemistry.

So after you have created the wrfinput_d01 file with chemistry on, simply

ln -s wrfinput_d01 wrf_chem_input_d01

Jordan
Hi Jordan,
I am not sure of the quality of the simulation output, but I can confirm that the alternate approach works.
Thanks for your time. Also it would be very helpful if this process could be directly implemented into the model without going through the whole process.

Neeldip

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