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

vertical_dim_type : “sigma_pressure” or “heights”, optional, default “sigma_pressure”

Vertical dimension type

  • “sigma_pressure”: Levels defined with ap/bp sigma pressure coordinates, with p = psurf * bp + ap

  • “heights”: Levels in meters above ground

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'

reverse_vcoord : bool, optional, default False

reverse the vertical coordinate or not

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  vertical_dim_type: XXXXX  # sigma_pressure|heights
17  sigma_a_var_name: XXXXX  # str
18  sigma_b_var_name: XXXXX  # str
19  pressure_unit: XXXXX  # Pa|hPa
20  reverse_vcoord: XXXXX  # bool
21  latitude_varname: XXXXX  # str
22  longitude_varname: XXXXX  # str
23  latitude_dimname: XXXXX  # str
24  longitude_dimname: XXXXX  # str
25  use_corners: XXXXX  # bool
26  extend_lat: XXXXX  # bool
27  extend_lon: XXXXX  # bool
28  lat_min: XXXXX  # float
29  lat_max: XXXXX  # float
30  delta_lat: XXXXX  # float
31  lon_min: XXXXX  # float
32  lon_max: XXXXX  # float
33  delta_lon: XXXXX  # float
34  regular_lon: XXXXX  # bool
35  regular_lat: XXXXX  # bool
36  force_centered_lat: XXXXX  # bool
37  force_centered_lon: XXXXX  # bool
38  sort_lat: XXXXX  # bool
39  sort_lon: XXXXX  # bool
40  drop_variables: XXXXX  # list
Contents