Gridded NetCDF domain gridded_netcdf/std

Gridded NetCDF domain gridded_netcdf/std#

Description#

Reads domain from a gridded NetCDF file

This plugin read the ‘latitude x longitude’ or ‘level x latitude x longitude’ domain from NetCDF files coordinates.

The latitude and longitude coordinate can be infered by their standard_name or long_name attribute (which should be 'latitude' or 'longitude'), Otherwise, .

If the latitude or longitude variable has a bounds attribute, the cell bounds are read from the variable given by this bounds attribute (which should be shaped as (n, 2)). Otherwise the bounds are computed with the max/min arguments and the lat/lon coordinates (assuming they represents the cells centers of a regular grid).

Vertical levels information (sigma pressure) is read only if the argument vertical_coord is provided. Vertical levels information can reside in a separate NetCDF file

YAML arguments#

The following arguments are used to configure the plugin. pyCIF will return an exception at the initialization if mandatory arguments are not specified, or if any argument does not fit accepted values or type:

Mandatory arguments#

file : str, mandatory

NetCDF file containing the grid coordinates

Optional arguments#

dir : str, optional, default “”

Directory containing file

dir_vcoord : str, optional, default “”

Directory containing file_vcoord. Use this argument if the vertical coordinates are not in file

file_vcoord : str, optional

NetCDF file containing the vertical coordinates. Use this argument if the vertical coordinates are not in file

vertical_coord : “mids” or “bounds”, optional

Read the domain’s vertical levels if this parameter is used. Should be ‘mids’ if the vertical coordinate represents the levels mid-points or ‘bounds’ if the vertical coordinate represents the levels boundaries. If this parameter is not used a domain single vertical level is created

  • “mids”: levels mid-points

  • “bounds”: levels boundaries

vertical_dim_name : str, optional, default “lev”

Vertical dimension name in file or file_vcoord

sigma_a_var_name : str, optional, default “ap”

‘sigma a’ variable name in file or file_vcoord

sigma_b_var_name : str, optional, default “bp”

‘sigma b’ variable name in file or file_vcoord

pressure_unit : “Pa” or “hPa”, optional

pressure units if different from units attributes in sigma `a` variable, should be ``'Pa' or 'hPa'

latitude_varname : str, optional, default “latitude”

Latitude coordinate variable name in file. If this argument is not provided, the latitude coordinate is found by its standard_name or long_name attribute (which should be 'latitude').

longitude_varname : str, optional, default “longitude”

Longitude coordinate variable name in file. If this argument is not provided, the longitude coordinate is found by its standard_name or long_name attribute (which should be 'longitude').

latitude_dimname : str, optional, default “latitude”

Latitude dimension name in file.

longitude_dimname : str, optional, default “longitude”

Longitude dimension name in file.

use_corners : bool, optional, default False

True if the longitudes and latitudes are used to defined the corners instead of gridcell centers

extend_lat : bool, optional, default False

Extend corner latitudes by one cell if nlat_corner != nlat + 1

extend_lon : bool, optional, default False

Extend corner longitudes by one cell if nlon_corner != nlon + 1

lat_min : float, optional, default -90.0

Minimum latitude

lat_max : float, optional, default 90.0

Maximum latitude

delta_lat : float, optional

Skip the reading/computation of latitude bounds and use regular gridcells with a size of delta_lat. delta_lat should divide lat_max - lat_min and be coherent with the NetCDF file dimensions.

lon_min : float, optional, default -180.0

Minimum longitude

lon_max : float, optional, default 180.0

Maximum longitude

delta_lon : float, optional

Skip the reading/computation of longitude bounds and use regular gridcells with a size of delta_lon. delta_lon should divide lon_max - lon_min and be coherent with the NetCDF file dimensions.

regular_lon : bool, optional, default True
Overwrites the default behaviour of regular domain

in zonal direction to compute corners. In this case, use the first and last delta to extent East and West

regular_lat : bool, optional, default True

Overwrites the default behaviour of regular domain in meridional direction to compute corners. In this case, use the first and last delta to extent South and North

force_centered_lat : bool, optional, default False

Force grid cells latitude to be centered between thier corners. Grid cells centers and corners will be read normally then the grid cells centers latitudes will be adjusted.

force_centered_lon : bool, optional, default False

Force grid cells longitude to be centered between thier corners. Grid cells centers and corners will be read normally then the grid cells centers longitudes will be adjusted.

sort_lat : bool, optional, default True

Sort latitudes in ascending order

sort_lon : bool, optional, default True

Sort longitudes in ascending order

drop_variables : list, optional, default []

List of variables to drop when reading the NetCDF files. This allows issues of MissingDimensionErrors as documented in, e.g., https://stackoverflow.com/questions/55109481/how-to-import-netcdf4-file-with-xarray-when-index-names-have-multiple-dimensions

YAML template#

Please find below a template for a YAML configuration:

 1domain:
 2  plugin:
 3    name: gridded_netcdf
 4    version: std
 5    type: domain
 6
 7    # Mandatory arguments
 8    file: XXXXX  # str
 9
10    # Optional arguments
11    dir: XXXXX  # str
12    dir_vcoord: XXXXX  # str
13    file_vcoord: XXXXX  # str
14    vertical_coord: XXXXX  # mids|bounds
15    vertical_dim_name: XXXXX  # str
16    sigma_a_var_name: XXXXX  # str
17    sigma_b_var_name: XXXXX  # str
18    pressure_unit: XXXXX  # Pa|hPa
19    latitude_varname: XXXXX  # str
20    longitude_varname: XXXXX  # str
21    latitude_dimname: XXXXX  # str
22    longitude_dimname: XXXXX  # str
23    use_corners: XXXXX  # bool
24    extend_lat: XXXXX  # bool
25    extend_lon: XXXXX  # bool
26    lat_min: XXXXX  # float
27    lat_max: XXXXX  # float
28    delta_lat: XXXXX  # float
29    lon_min: XXXXX  # float
30    lon_max: XXXXX  # float
31    delta_lon: XXXXX  # float
32    regular_lon: XXXXX  # bool
33    regular_lat: XXXXX  # bool
34    force_centered_lat: XXXXX  # bool
35    force_centered_lon: XXXXX  # bool
36    sort_lat: XXXXX  # bool
37    sort_lon: XXXXX  # bool
38    drop_variables: XXXXX  # list
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