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Nested WRF simulation without smoothing

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I'm having trouble running a nested simulation without the topography being greatly smoothened despite setting smooth_option = 0 in GEOGRID.TBL and namelist.input. The topography seems to be correctly loaded in the file, but the wrfout_d04 seems to use topography based on a smoothened version of, as illustrated in the attached images. The images are visualized in ParaView by first converting the .nc files to .vts files using SISO (i.e. siso -f vts --last --coords=utm:32u). Similar plots are obtained using ncview. I am using WRF Model Version 4.2.1 and WPS Version 4.2.

How do I avoid this smoothening such that maximal resolution (at least for the topography) for the innermost nested domain is obtained?


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Hi, Zetison ,
I understand that you try to run a nested case with high resolution topography in you child domain. Please let me know if I am wrong.
if this is the case, please modify your namelist.wps by setting
geog_data_res     = 'default', 'default', 'default', 'default',

Then try again.
Hi, Ming Chen,

Thank you for your reply. I had uploaded incorrect namelist.wps. The correct one had the default option on all domains in geog_data_res. I reran the case to be sure, and so the attached files should now be correct.


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Hi, Zetison ,

I have run a test case using your namelist.wps. Please see the attached plots that show topography in D01 and D04. It is clear that the terrain in D04 demonstrates more detailed structure. These plots are simply from ncdiew. I am not familiar with Paraview and thus cannot judge whether the issue you have is derived from this specific software. Anyway please take a look and let me know if you have more questions.


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Hi Ming Chen,

Yes, the file seems fine (with correct resolution). However, if you visualize the HGT field the same level of resolution of the topography is not obtained.


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HI, Zetison,
I actually run real.exe/wrf,exe and I can obtain high-resolution data for D04, just like the one shown in I believe your issue is related to an incorrect namely setting.
Please change the lines below from:
dx = 27794.37,
dy = 27794.37,

dx = 27794.37,9264.79,3088.263,1029.421
dy = 27794.37,9264.79,3088.263,1029.421

Then try again. Please let me know if you still cannot obtain high-resolution HGT data for D04.

Hi, Ming,

I tried your suggestion, but with no success, sadly. How did you verify the correct resolution? Through ncview?


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I just wonder what software package did you use to look at the data? I simply look at wrfinput_d01 and wrfinput_d04 by ncview, and the topography in D04 obviously has more details. By the way, I run the test using WRFV4.3. However, I believe the the older version will also yield correct results.
I found the mistake: I assumed "input_from_file = .true.," implied "input_from_file = .true.,.true.,.true.,.true.,", which does not seem to be the case. I guess .false. is the default value (could not find where this is stated though).

Thanks a lot for your help and patience, Ming!


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Hi, Zetison
thanks for the update. I am glad that you found the problem. The default option of input_from_file is always true, and I didn't realize that it could be false for nested domains. Thanks for this kind information.