CDO

Hello,
It is similar to the problem I reported few years back - https://code.mpimet.mpg.de/boards/2/topics/5239?r=5246#message-5246 and I am using cdo 1.9.7. I am trying to merge several netCDF files. I have NCAR reanalysis files for uwnd, vwnd and air temperatures at different levels for a single day at different times.

netcdf uwnd_1000_2020_11_3_00Z {
dimensions:
time = UNLIMITED ; // (4 currently)
lat = 73 ;
level = 1 ;
lon = 144 ;

So I need to merge all uwnd files first, then vwnd files next and then air temp files finally. Then I need to merge all of the merged files together. This part works fine

Then I do a timmean on the merged file in Python in the following way -

cdo = Cdo()
cdo.timmean(input='PFile.nc',output='AFile.nc')


and I get a spurious dimension. Where am I going wrong ?

netcdf AFile {
dimensions:
time = UNLIMITED ; // (1 currently)
bnds = 2 ;
lon = 144 ;
lat = 73 ;
level = 17 ;
variables:
double time(time) ;
time:standard_name = "time" ;
time:long_name = "Time" ;
time:bounds = "time_bnds" ;
time:units = "hours since 1800-01-01 00:00:0.0" ;
time:calendar = "standard" ;
time:axis = "T" ;
double time_bnds(time, bnds) ;
float lon(lon) ;
lon:standard_name = "longitude" ;
lon:long_name = "Longitude" ;
lon:units = "degrees_east" ;
lon:axis = "X" ;
float lat(lat) ;
lat:standard_name = "latitude" ;
lat:long_name = "Latitude" ;
lat:units = "degrees_north" ;
lat:axis = "Y" ;
float level(level) ;
level:standard_name = "air_pressure" ;
level:long_name = "Level" ;
level:units = "millibar" ;
level:positive = "down" ;
level:axis = "Z" ;
level:actual_range = 1000.f, 10.f ;
level:GRIB_id = 100s ;
level:GRIB_name = "hPa" ;
float air(time, level, lat, lon) ;
air:long_name = "4xDaily Air temperature" ;
air:units = "degK" ;
air:_FillValue = -9.96921e+36f ;
air:missing_value = -9.96921e+36f ;
air:precision = 2s ;
air:least_significant_digit = 1s ;
air:GRIB_id = 11s ;
air:GRIB_name = "TMP" ;
air:var_desc = "Air temperature" ;
air:level_desc = "Multiple levels" ;
air:statistic = "Individual Obs" ;
air:parent_stat = "Other" ;
air:dataset = "NCEP Reanalysis" ;
air:actual_range = 173.7f, 321.2f ;
air:_ChunkSizes = 1, 1, 73, 144 ;
float uwnd(time, level, lat, lon) ;
uwnd:long_name = "4xDaily U-wind" ;
uwnd:units = "m/s" ;
uwnd:_FillValue = -9.96921e+36f ;
uwnd:missing_value = -9.96921e+36f ;
uwnd:precision = 2s ;
uwnd:least_significant_digit = 1s ;
uwnd:GRIB_id = 33s ;
uwnd:GRIB_name = "UGRD" ;
uwnd:var_desc = "u-wind" ;
uwnd:level_desc = "Multiple levels" ;
uwnd:statistic = "Individual Obs" ;
uwnd:parent_stat = "Other" ;
uwnd:dataset = "NCEP Reanalysis" ;
uwnd:actual_range = -100.1f, 138.6f ;
uwnd:_ChunkSizes = 1, 1, 73, 144 ;
float vwnd(time, level, lat, lon) ;
vwnd:long_name = "4xDaily V wind" ;
vwnd:units = "m/s" ;
vwnd:_FillValue = -9.96921e+36f ;
vwnd:missing_value = -9.96921e+36f ;
vwnd:precision = 2s ;
vwnd:least_significant_digit = 1s ;
vwnd:GRIB_id = 34s ;
vwnd:GRIB_name = "VGRD" ;
vwnd:var_desc = "v-wind" ;
vwnd:level_desc = "Multiple levels" ;
vwnd:statistic = "Individual Obs" ;
vwnd:parent_stat = "Other" ;
vwnd:dataset = "NCEP Reanalysis" ;
vwnd:actual_range = -108.f, 100.1f ;
vwnd:_ChunkSizes = 1, 1, 73, 144 ;