Gridgen: sources for using the tool

[jaslanli]

Hi. Can someone please explain working p=principles of Gridgen tool?

I've gone through lecture and tutorial doc and trying to generate necessary grid files for my model.

I use Gebco bathymetry data source and file I get is .nc formatted data file. My expectation is to cerate .bot and .mask files out of raw .nc data so to have all necessary inputs (namelists.nml, ww3_grid.nml, data.bot, data.mask) for running ww3_grid program.

In above referred tutorial doc, pre-prepared namelist file (gridgen.ZA-7M.nml) is used as an input. Can someone please explain how do we need to prepare namelist file at this stage?

Thanks in advance!

[mickaelaccensi]

Hi,

In the tutorial, there is an appendix explaining how to create the ww3_grid.nml from your .meta file created with gridgen.

Best,

[jaslanli]

Hi, thanks for your reply.
Isn't it about further step? - creating ww3_grid.nml.

I'm still in the beginning stage, trying to apply Gridgen for creating .bot and .mask files.

I think after this I can start creating the ww3_grid.nml from .meta file created with Gridgen.

[jaslanli]

Hi,

Thanks for help. I followed Appendix H in tutorial, and could generate relevant grid files from raw bathymetry data as expected.
One question, while performing the last step - Saving files, I'm getting fails on creation of meta file after running this command:

write_ww3meta([data_dir,'/',fname],[nml_dir,'/gridgen.',fname,'.nml'],'RECT',lon,lat,1/depth_scale,1/obstr_scale,1.0);

As a result I get .meta file which is empty. Any idea how I can fix it?

>> write_ww3meta([data_dir,'/',fname],[nml_dir,'/gridgen.',fname,'.nml'],'RECT',lon,lat,1/depth_scale,1/obstr_scale,1.0);
Error using fgets
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in fgetl (line 4)
[tline,lt] = fgets(fid);
             ^^^^^^^^^^
Error in read_namelist (line 29)
line=fgetl(fid);
     ^^^^^^^^^^
Error in write_ww3meta (line 57)
init_nml    = read_namelist(fname_nml,'GRID_INIT');
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Thank you!