Altering WRF's initial conditions

Questions/topics related to the first-guess input meteorological data, and Vtables
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koko_a
Posts: 9
Joined: Sun May 26, 2019 10:05 am

Altering WRF's initial conditions

Post by koko_a » Tue Nov 05, 2019 6:25 am

Hi,

I'm running WRF 3.9 using ERA-Interim data (GRIB) as input.
I wonder what is the best way to alter the input data (as in pseudo global warming studies. E.g., change the vertical distribution of humidity, lapse rate).
I guess I can try to edit either the GRIB files or the intermediate files.
What do you think is better?
Can you recommend a simple way to do so?

Thanks,
Koko

kwerner
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Joined: Wed Feb 14, 2018 9:21 pm

Re: Altering WRF's initial conditions

Post by kwerner » Tue Nov 05, 2019 4:13 pm

This post has been moved to the WPS/Meteorological Input Data section of the forum. Someone will respond to your email soon.
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Ming Chen
Posts: 1013
Joined: Mon Apr 23, 2018 9:42 pm

Re: Altering WRF's initial conditions

Post by Ming Chen » Thu Nov 07, 2019 10:17 pm

You can change the met_em file, suppose both the initial and boundary conditions need to change. Please see the utility that might be helpful for you:

http://www2.mmm.ucar.edu/wrf/OnLineTuto ... ptions.php
WRF Help Desk

koko_a
Posts: 9
Joined: Sun May 26, 2019 10:05 am

Re: Altering WRF's initial conditions

Post by koko_a » Mon Jan 13, 2020 2:51 pm

Hi Ming Chen, thanks for the reply.

Would changing the met_em files be better (easier) than changing the wrfinput_d0* files?
If editing the wrfinput files is easier, do I need to edit the wrfbdy file as well? Would it make any sense?

Thanks,
Koko

koko_a
Posts: 9
Joined: Sun May 26, 2019 10:05 am

Re: Altering WRF's initial conditions

Post by koko_a » Wed Jan 15, 2020 9:20 am

OK, it seems more logical to change the met_em files.
However, now I've noticed I'm getting met_em for each time interval for each of the domains.
I thought I only need the initial met_em.d0*, and all time intervals for met_em.d01.
Is this correct?

If it is, it means that I only need to change those files...
So why am I getting met_em for all time intervals for all domains?

Attached are example namelist (WPS and input) files.

Thanks,
Koko
Attachments
namelist.wps
(1.52 KiB) Downloaded 8 times
namelist.input
(4.68 KiB) Downloaded 9 times

Ming Chen
Posts: 1013
Joined: Mon Apr 23, 2018 9:42 pm

Re: Altering WRF's initial conditions

Post by Ming Chen » Thu Jan 30, 2020 11:16 pm

For your case, I suggest to change all met_em files, because you probably need modification not only for wrfinput, but also wrfbdy. If you don't change wrfbdy, it means that only your initial condition is changed.
WRF Help Desk

jbasconcillo
Posts: 5
Joined: Fri Jul 03, 2020 4:12 am

Re: Altering WRF's initial conditions

Post by jbasconcillo » Fri Jul 03, 2020 5:48 am

Hi Ming Chen:

How would you consider the memory of the previous value of the variable? Say, for T2M, it has effect on RH of course. And if I change T2M, how do I consider change RH? Do I need to change all variables in this context?

Ming Chen
Posts: 1013
Joined: Mon Apr 23, 2018 9:42 pm

Re: Altering WRF's initial conditions

Post by Ming Chen » Mon Jul 06, 2020 7:49 pm

It depends on your specific case. You need to make reasonable changes and don't violate the basic laws of the atmospheric physics and dynamics.
WRF Help Desk

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