Wind data

[fed1942]

What format should the wind data file have? For example, i have a wind data file (U, V) with 2 blocks of 192 columns (0 to 358.125) and 94 rows (-88.5 to 88.5) for each time step. Two questions:

Is the arrangement of the data correct (192x94)?
Is it correct that the data is ordered vertically from south to north (-88.5 to 88.5)?

Thank you in advance.

[aliabdolali]

You can try netcdf and then utilize ww3_prnc or go with ascii and try ww3_prep program.
There is an example for global wind in regtests/ww3_ufs1.1/input

[fed1942]

I already have a wind data file that can be read with ww3_prep. The problem i have is that the results i got using ww3_multi are not good. Knowing that there is no problem with the grids that i am using (bathymetry, obtruction grids, masks), i suspect that something is not right with the winds. I think it may have to do with the second question i asked.

[ukmo-ccbunney]

Is the arrangement of the data correct (192x94)? Is it correct that the data is ordered vertically from south to north (-88.5 to 88.5)?

Hello @fed1942 .
That is fine for the data to be ordered south to north in your input file, just be sure to use the correct IDLA (layout indicator) value in your ww3_prep.inp (or nml) file. From the docs:

$      IDLA : Layout indicator :
$                  1   : Read line-by-line bottom to top.
$                  2   : Like 1, single read statement.
$                  3   : Read line-by-line top to bottom.
$                  4   : Like 3, single read statement.

So in your case, if the first line in your input file is your southern most latitude row, then you should be using ILDA=1 or 2 (I think I have got that the right way round!).

Also - if you suspect your winds are being read in incorrectly, then you can always check by outputting the wind field from the model and plotting the values as a visual check against your original field.