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Does the remapcon operator depend on the unit of parameters?

Added by Beata Szabo-Takacs almost 8 years ago

Dear All,

I have a netCDF file about temperature where the temperature is declared in K but the values are in °C, by chance. Its grid resolution is 11 km. I remapped this netCDF with remapcon operator to a 25 km resolution netCDF file. The resulted temperature values are between -3.5539e+04 8.0198e+04 °C.

Is it possible that these unreliable values are stem from the mistake that the original temperature values were in °C instead of K?

Thank you for your answer in advance!
Beata


Replies (3)

RE: Does the remapcon operator depend on the unit of parameters? - Added by Ralf Mueller almost 8 years ago

In general: No.

But please upload the file - it's hard to say something reliable without it

RE: Does the remapcon operator depend on the unit of parameters? - Added by Beata Szabo-Takacs almost 8 years ago

Thank you for your reply! I attached a netCDF about the first four days of tas in 2021.

sample.nc (3.95 MB) sample.nc

RE: Does the remapcon operator depend on the unit of parameters? - Added by Ralf Mueller almost 8 years ago

With cdo-1.7.1 I get the following error:

ram@luthien:~/Downloads cdo remapcon,r180x90 sample.nc nnsample.nc                                                                                                                                                         
cdo remapcon (Abort): Grid cell corner coordinates missing!

Could be that the 1.6.8 version you used did not catch this and produces wrong interpolation values.
What command did you use? IMO CDO cannot compute the source cell area because their coordinate bounds are missing,

You might be more successful in remappping with gmt: http://gmt.soest.hawaii.edu/doc/latest/grdproject.html

BTW, you can change the unit of your temperature variable with the setunit operator or the NCO attribute editor ncatted

  • cdo -setunit,"deg_C" -selname,tas sample.nc tasInCelsius.nc
  • ncatted -a unit,tas,m,c,"deg_C" sample.nc
    (1-3/3)