pycif.plugins.datastreams.fields.netcdf_cams — API reference

Configuration reference: netcdf_cams plugin

pycif.plugins.datastreams.fields.netcdf_cams.fetch.fetch(ref_dir, ref_file, input_interval, target_dir, tracer=None, component=None)

Fetch monthly CAMS NetCDF files and their sub-interval time steps.

Forces the requested period to full months, then for each month (stepped at tracer.file_freq) reads the number of time steps in the corresponding file to build one sub-interval per time step, and links the file into target_dir.

Parameters:

• ref_dir – directory where the original files are found.

• ref_file – (template) name of the original files.

• input_interval – list of two dates, the beginning and end of the simulation.

• target_dir – directory where links to the original files are created.

• tracer – the fields Plugin, giving access to file_freq.

• component – unused, accepted for interface compatibility.

Returns:

for each monthly date, the file path repeated once

per time step found in that file.

list_dates: for each monthly date, the list of [start, end]

sub-intervals covered by that file’s time steps.

Return type:

list_files

pycif.plugins.datastreams.fields.netcdf_cams.get_domain.get_domain(ref_dir, ref_file, input_interval, target_dir, tracer=None)

Build the CAMS grid Domain from one of the tracer’s input files.

Reads longitude/latitude from the first available input file, computes cell corners assuming a regular grid, and builds the vertical hybrid-sigma coordinates either as interface values (ap/bp, read from the file, or from a CSV given by tracer.aibi_file when tracer.aibi_name is set) or as mid-level values (hyam/hybm).

Parameters:

• ref_dir – unused, accepted for interface compatibility.

• ref_file – unused, accepted for interface compatibility.

• input_interval – unused, accepted for interface compatibility.

• target_dir – unused, accepted for interface compatibility.

• tracer – the fields Plugin; tracer.input_files is used to find a reference file, and tracer.aibi_name/tracer.aibi_file control how the vertical coordinate is resolved.

Returns:

the CAMS grid domain.

Return type:

Domain

Raises:

CifError – if no reference file can be found among tracer.input_files.

pycif.plugins.datastreams.fields.netcdf_cams.read.read(self, name, varnames, dates, files, interpol_flx=False, comp_type=None, tracer=None, ddi=None, **kwargs)

Get BCs from raw CAMS files and load them into a pyCIF variable.

For each requested date, computes the time index within the monthly file from the file’s number of time steps, reads the variable, and flips the latitude axis to increasing order (and the vertical axis if tracer.flip_level is set) as needed.

Parameters:

• self – the BC Plugin

• name – the name of the component

• varnames – variable name to extract if different from name

• dates – list of [start, end] date pairs to extract

• files – list of file paths matching dates

• interpol_flx – unused, accepted for interface compatibility

• comp_type – unused, accepted for interface compatibility

• tracer – the fields Plugin; tracer.flip_level controls whether the vertical axis is flipped

• ddi – must not be None; only used to validate the call, not otherwise referenced

Returns:

xarray.DataArray with dims (time, lev, lat, lon).

Raises:

CifError – if ddi is None.