CDO

Dear all,

I have the following (see ncdump -h and cdo sinfov information below) netcdf file of zonal wind on a monthly scale for 100 years. I want the monthly mean of the 100 years of data. I have run cdo monmean input.nc output.nc and even cdo monmean -selvar,ua input.nc output.nc for this, but the output in both instances still has 1200 time bands instead of 12. I wonder if anyone has some advice on this as I have no idea why this command is not working.

ncdump:
ua_Amon_EC-Earth3-LR_midPliocene-eoi400_r1i1p1f1_gr_330701-340612_remap1deg_850hpa {
dimensions:
time = UNLIMITED ; // (1200 currently)
bnds = 2 ;
lon = 360 ;
lat = 180 ;
plev = 1 ;
variables:
double time(time) ;
time:standard_name = "time" ;
time:long_name = "time" ;
time:bounds = "time_bnds" ;
time:units = "days since 1850-01-01 00:00:00" ;
time:calendar = "proleptic_gregorian" ;
time:axis = "T" ;
double time_bnds(time, bnds) ;
double lon(lon) ;
lon:standard_name = "longitude" ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
lon:axis = "X" ;
double lat(lat) ;
lat:standard_name = "latitude" ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
lat:axis = "Y" ;
double plev(plev) ;
plev:standard_name = "air_pressure" ;
plev:long_name = "pressure" ;
plev:units = "Pa" ;
plev:positive = "down" ;
plev:axis = "Z" ;
float ua(time, plev, lat, lon) ;
ua:standard_name = "eastward_wind" ;
ua:long_name = "Eastward Wind" ;
ua:units = "m s-1" ;
ua:_FillValue = 1.e+20f ;
ua:missing_value = 1.e+20f ;
ua:comment = "Zonal wind (positive in a eastward direction)." ;
ua:cell_methods = "time: mean" ;
ua:cell_measures = "area: areacella" ;
ua:history = "2020-03-22T08:19:48Z altered by CMOR: Reordered dimensions, original order: lat lon plev time." ;

sinfov:
File format : NetCDF4 classic
-1 : Institut Source T Steptype Levels Num Points Num Dtype : Parameter name
1 : unknown EC-Earth3-LR v instant 1 1 64800 1 F32 : ua
Grid coordinates :
1 : lonlat : points=64800 (360x180)
lon : 0 to 359 by 1 degrees_east circular
lat : -89.5 to 89.5 by 1 degrees_north
Vertical coordinates :
1 : pressure : levels=1
plev : 85000 Pa
Time coordinate : 1200 steps
RefTime = 1850-01-01 00:00:00 Units = days Calendar = proleptic_gregorian Bounds = true
YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss
3307-01-16 12:00:00 3307-02-15 00:00:00 3307-03-16 12:00:00 3307-04-16 00:00:00
3307-05-16 12:00:00 3307-06-16 00:00:00 3307-07-16 12:00:00 3307-08-16 12:00:00
3307-09-16 00:00:00 3307-10-16 12:00:00 3307-11-16 00:00:00 3307-12-16 12:00:00
3308-01-16 12:00:00 3308-02-15 12:00:00 3308-03-16 12:00:00 3308-04-16 00:00:00
3308-05-16 12:00:00 3308-06-16 00:00:00 3308-07-16 12:00:00 3308-08-16 12:00:00
3308-09-16 00:00:00 3308-10-16 12:00:00 3308-11-16 00:00:00 3308-12-16 12:00:00
3309-01-16 12:00:00 3309-02-15 00:00:00 3309-03-16 12:00:00 3309-04-16 00:00:00
3309-05-16 12:00:00 3309-06-16 00:00:00 3309-07-16 12:00:00 3309-08-16 12:00:00
3309-09-16 00:00:00 3309-10-16 12:00:00 3309-11-16 00:00:00 3309-12-16 12:00:00
3310-01-16 12:00:00 3310-02-15 00:00:00 3310-03-16 12:00:00 3310-04-16 00:00:00
3310-05-16 12:00:00 3310-06-16 00:00:00 3310-07-16 12:00:00 3310-08-16 12:00:00
3310-09-16 00:00:00 3310-10-16 12:00:00 3310-11-16 00:00:00 3310-12-16 12:00:00
3311-01-16 12:00:00 3311-02-15 00:00:00 3311-03-16 12:00:00 3311-04-16 00:00:00
3311-05-16 12:00:00 3311-06-16 00:00:00 3311-07-16 12:00:00 3311-08-16 12:00:00
3311-09-16 00:00:00 3311-10-16 12:00:00 3311-11-16 00:00:00 3311-12-16 12:00:00
................................................................................
................................................................................
..
3402-01-16 12:00:00 3402-02-15 00:00:00 3402-03-16 12:00:00 3402-04-16 00:00:00
3402-05-16 12:00:00 3402-06-16 00:00:00 3402-07-16 12:00:00 3402-08-16 12:00:00
3402-09-16 00:00:00 3402-10-16 12:00:00 3402-11-16 00:00:00 3402-12-16 12:00:00
3403-01-16 12:00:00 3403-02-15 00:00:00 3403-03-16 12:00:00 3403-04-16 00:00:00
3403-05-16 12:00:00 3403-06-16 00:00:00 3403-07-16 12:00:00 3403-08-16 12:00:00
3403-09-16 00:00:00 3403-10-16 12:00:00 3403-11-16 00:00:00 3403-12-16 12:00:00
3404-01-16 12:00:00 3404-02-15 12:00:00 3404-03-16 12:00:00 3404-04-16 00:00:00
3404-05-16 12:00:00 3404-06-16 00:00:00 3404-07-16 12:00:00 3404-08-16 12:00:00
3404-09-16 00:00:00 3404-10-16 12:00:00 3404-11-16 00:00:00 3404-12-16 12:00:00
3405-01-16 12:00:00 3405-02-15 00:00:00 3405-03-16 12:00:00 3405-04-16 00:00:00
3405-05-16 12:00:00 3405-06-16 00:00:00 3405-07-16 12:00:00 3405-08-16 12:00:00
3405-09-16 00:00:00 3405-10-16 12:00:00 3405-11-16 00:00:00 3405-12-16 12:00:00
3406-01-16 12:00:00 3406-02-15 00:00:00 3406-03-16 12:00:00 3406-04-16 00:00:00
3406-05-16 12:00:00 3406-06-16 00:00:00 3406-07-16 12:00:00 3406-08-16 12:00:00
3406-09-16 00:00:00 3406-10-16 12:00:00 3406-11-16 00:00:00 3406-12-16 12:00:00

Kindest regards,
Sarah