CDO

Dear CDO users,

as a CDO newbie I am wondering of how to make use of cdo to process wrf-output files. I performed climate simulations from 1961-1990 and 2020-2050 with a resolution of 6 hours. I stored the output in monthly files. The overall goal is to calculate the climate change signal (future minus past) for the domain of interest and on a monthly basis, i.e. are future Jan, Feb, etc. expected to be warmer/cooler?. Finally, I would like to come up with a) 12 values for the past (long term-mean values for 1961-1990) and 12 values for the future. b) In addition to that, I would like to compare each month in a spatial sense (map of domain for future Jan values minus map of domain for past values).
I was reaading the manual, but am still not sure how to do that. I think several steps will be necessary:
- calculate mean values for each month (Jan 1961, Jan 1962, Jan 1963, etc.); the output of e.g. the Jan 1961 ends at 01/02/1961 at 00:00:00 h, thus, the monmean function will possibly create 2 files out of 1 wrfoutput file?!
- calculate long-term mean values (Jan1961-1990)
- concatenate the files to one file (not sure if necessary?)
- perform the same steps for the future time slice
- for aspect a) (see above): average the values over the domain of interest
- calculate differences

I am grateful for any hints on that, suggested functions, order of commands, etc. I also found in manual that these steps can be done at once (pipe!)