ncl output, red-colored domains

[hconel]

Hi,
I'm testing geogrid with different resolutions and multiple (3-4) domains. In the ncl output, 3rd and 4th domains are shown with red color. I don't see any warnings/errors in the ungrib/geogrid logs. I've searched the guides but couldn't find the reason, is the red color a problem? If not, what does it indicate?

Here are some screenshots:

4 domains

3 domains

Regards,
Huseyin

 

[Ming Chen]

Please send me your namelist.wps to take a look. thanks.

 

[hconel]

Mr. Chen,
Here is the namelist.wps file I used for the 4-domains case:

&share 

              wrf_core =  'ARW' ,
               max_dom =      4 ,
            start_date =   '2021-10-18_03:00:00',  '2021-10-18_03:00:00',  '2021-10-18_03:00:00',  '2021-10-18_03:00:00', 
              end_date =   '2021-10-18_12:00:00',  '2021-10-18_12:00:00',  '2021-10-18_12:00:00',  '2021-10-18_12:00:00', 
      interval_seconds =  10800 ,

/ 
 
&geogrid 

             parent_id =      1,     1,     2,     3, 
     parent_grid_ratio =      1,     4,     2,     3, 
        i_parent_start =      1,    29,    46,    16, 
        j_parent_start =      1,    14,    40,    22, 
                  e_we =     85,   113,    45,    43, 
                  e_sn =     53,   105,    53,    31, 
                    dx =   6000 ,
                    dy =   6000 ,
              map_proj =        'lambert' ,
               ref_lat =       39.00 ,
               ref_lon =       35.45 ,
              truelat1 =       39.00 ,
             stand_lon =       35.45 ,
        geog_data_path =  '/home/hconel/OpenFOAM/Build_WRF/WPS_GEOG/' ,

/ 
 
&ungrib 

            out_format =  'WPS' ,
                prefix =  'FILE' ,

/ 
 
&metgrid 

               fg_name =  'FILE' ,
       io_form_metgrid =  2 ,

/

The nesting may not make much sense, it is purely for learning purposes
Just after I created the topic, I have seen suggestions like "each domain should have at least 100x100 nodes" and "the gap between domain boundaries should be around 1/3 of the parent nodes" in some tutorial videos. Maybe that is the case?
Thanks.

 

[Ming Chen]

Hi,
Your namelist.wps looks fine except the nesting ratio. I would suggest that you change the nesting ratio to odd number, for example 3 or 5. The even number of nesting ratio may cause issues later during the feedback between parent and child domain..
The red color in your plot is specified in the NCL script. I don't think the color indicates anything wrong.

 

[hconel]

Thanks for your continuing support Mr. Chen,
Regards