CDO

Hi Andreas,

Try the undocumented CDO operator fillmiss. This operator fills missing values by a bilinear interpolation of the four surrounding points. The status of this operator is experimental and it works only on rectilinear grids.

Cheers,
Uwe

Uwe,

thanks a lot for this! For my use case, it works like a charm. Wow.

I should note, however, that extrapolation towards the poles doesn't seem to work properly. This is my grid:

gridtype  = lonlat
gridsize  = 29040
xname     = lon
xlongname = longitude
xunits    = degrees_east
yname     = lat
ylongname = latitude
yunits    = degrees_north
xsize     = 240
ysize     = 121
xfirst    = 0
xinc      = 1.5
yfirst    = -90
yinc      = 1.5

All my values at 90N and 90S are nan. When using the fillmiss operator, the values from 88.5° are simply copied to 90°, leading to 240 different values for the pole, which at least physically doesn't make sense.

In my use case, it doesn't matter, but I just wanted to point you to this issue.

Cheers, Andreas.

Just a comment, (as this is probably best fixed with setmisstonn),
the north issue is as a result of the boundary (north) being wrong. It may be best to set all boundaries to zero prior to using fillmiss.

Another comment. Rectilinear lat-lon grids that include 90N/S (as a center point of a grid cell) are a very bad practice, although they are still commonly used.