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utilizing expression to compute a particular variable?

Added by Ameer Muhammad over 3 years ago

I would like to compute Relative Humidity (RH) using three other variables that comes in NetCDF file. I have merged the three variables (Pressure_UARB, specific_UARB, and SurfaceTemp_UARB) in one big file (sh_ps_tas_merged.nc) and used the following code to compute RH.nc.

cdo 'rh=0.263*Pressure_UARB*specific_UARB/exp((17.67*(SurfaceTemp_UARB-273.15)/(SurfaceTemp_UARB-29.95)))' sh_ps_tas_merged.nc RH.nc

However, i am getting the attached error- any help would be appreciated.

error.PNG (10.3 KB) error.PNG

Replies (2)

RE: utilizing expression to compute a particular variable? - Added by Karin Meier-Fleischer over 3 years ago

Hi Ameer,

you've missed the expr operator.

cdo -expr,'rh=0.263*Pressure_UARB*specific_UARB/exp((17.67*(SurfaceTemp_UARB-273.15)/(SurfaceTemp_UARB-29.95)))' sh_ps_tas_merged.nc RH.nc

-Karin

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