ccdfzonalmean : compute the global zonal mean of the given variable

Compute the zonal mean of the given variable from the input file. Zonal mean is in fact the mean value computed along the I coordinate. The result is a vertical slice, in the meridional direction.

This is the wrapping around the native cdfzonalmean operator assuming its usage is:

cdfzonalmean IN-file point_type [ BASIN-file] **[-debug]**
... [-var var1,var2,..] [-max ] **[-pdep | --positive_depths]
[-ndep_in ]**

CliMAF optional arguments are the ones between ‘**’

See also ccdfzonalmean_bas for getting a zonal mean in a specified sub-basin.

References : http://www.drakkar-ocean.eu/tools

Provider / contact : climaf at meteo dot fr for the wrapping

Inputs (in the order of CliMAF call):

  • any dataset (but only one)

Mandatory argument:

  • point_type : indicate the location on C-grid (T|U|V|F|W)

Optional arguments:

  • opt : may be used to pass keys -pdep (use positive depths in the output file), -ndep_in (negative depths are used in the input file) and/or -debug (to add some print for debug)

Required files: Files mesh_hgr.nc, mesh_zgr.nc, mask.nc must be in the current directory (use fixed_fields() for that; see example below).

Outputs:

  • main output : a netcdf file (variable : zoxxxx_glo, where zo replace vo/so prefix of the input variable)

Climaf call example:: For more examples which are systematically tested, see cdftools.py

>>> # How to get required files for Cdftools cdfzonalmean binary
>>> fixed_fields('ccdfzonalmean',
 ... ('mask.nc',    '/data/climaf/${project}/${model}/ORCA1_mesh_mask.nc'),
 ... ('mesh_hgr.nc','/data/climaf/${project}/${model}/ORCA1_mesh_hgr.nc'),
 ... ('mesh_zgr.nc','/data/climaf/${project}/${model}/ORCA1_mesh_zgr.nc'))
>>> # For example, define dataset with meridional velocity component ("vo")
>>> dvo=ds(simulation="PRE6CPLCr2alb", variable="vo", period="199807", realm="O")
>>> my_cdfzmean=ccdfzonalmean(dvo,point_type='V')
>>> cfile(my_cdfzmean) # to compute the global zonal mean and get a filename with the result
>>> my_cdfzmean2=ccdfzonalmean(dvo,point_type='V', opt='-debug -pdep')
>>> cfile(my_cdfzmean2)

Implementation: The operator is implemented as a binary using cdftools cdfzonalmean operator.