CDO

I want to convert a WRF output "wrfout_d01.e001" to rotated coordinates in COSMO model.

First question: is it necessary to extract data for each variable and do the coordinate transformation (because of the staggered C-grid, the grid size for each
variable is different)?

Second question: I did select one specific variable (e.g., u) by "cdo selvar,U wrfout_d01.e001 wrf_u.nc" and it was successful. But

cdo remapdis,outgrid.txt wrf_u.nc cosmo_nc

did not result in correct coordinate transformation, i.e., coordinates changed but Pole not rotated, and there are not valid data for u.

The content of outgrid.txt is

gridtype = projection
xsize = 547
ysize = 451
xunits = "degrees"
yunits = "degrees"
xfirst = -1.0
xinc = 0.0269786784
yfirst = 2.0
yinc = 0.0269786784
grid_mapping_name = rotated_latitude_longitude
grid_north_pole_longitude = -170.0
grid_north_pole_latitude = 40.0

Does anyone what was wrong? Many thanks!