CDO

let me search that for you ;-)

https://code.mpimet.mpg.de/projects/cdo/wiki/FAQ#How-can-I-select-variables-and-save-it-to-a-new-file

Dear Ralf,

Thanks so much for your prompt response. I found it very useful and working.

Thanks and regards,

Catalyst

happy2help ;-)

Dear Ralf,

Please, how can I extract relative humidity at 2m from wrf output? Thanks in anticipation.

Catalyst

Really? Please, read the Tutorial and the FAQ. This is a basic question which you can find in the documentation and you can search it via google.

Do you know the standard_name of the variable? There are many different variable names and files.
If you don't know the variable name try the next, maybe it returns the name ...

ncdump -h wrf_file | grep humidity

or

ncdump -h wrf_file | grep HUMIDITY

Assume it is rhum then you can select it with

cdo -selname,rhum infile outfile

It is always good to have a look at the content of the data file you want to work with!

-Karin

Dear Karin,

Thanks for your reply. Unfortunately, variable "relative humidity" can not be found in the wrf file. I think it has to be calculated using some available variables.
Further help would still be appreciated.

Catalyst

Dear Karin,

I have a file that is in .txt format (as atached). It is my observation data. I want to do some statistical analysis by comparing my model results with the observed data using CDO. How can I convert it to netcdf format to make it being in the same format with my model data and use CDO for the analysis? Please, note that I used CDO to extract the variables from the model.

Thanks for your usual help.

Catalyst