bom_txt_to_nc.py

"""Convert a BoM temperature anomaly txt file to netCDF"""

import argparse
import pdb

import cftime
import xarray as xr
import numpy as np

from unseen import fileio


def main(args):
    """Run the program."""

    with open(args.infile) as f:
        lines = f.readlines()[1:]

    times = []
    values = []
    for line in lines:
        date, value = line.split()
        year = int(date[6:10])
        month = int(date[10:12])
        times.append(cftime.DatetimeJulian(year, month, 15))
        values.append(float(value))

    var_attrs = {
        'standard_name': 'air_temperature',
        'long_name': 'DJF Mean Near-Surface Air Temperature for Australia',
        'units' : 'C',
    }

    ds = xr.Dataset(
        {
            'tas': xr.DataArray(
                data = np.array(values) + args.baseline_temperature,
                dims = ['time'],
                coords = {'time': np.array(times)},
                attrs = var_attrs
            )
        },
            attrs = {
                'history': fileio.get_new_log(),
                'source': args.source
            }
        )
    ds['time'].attrs['long_name'] = 'time'
    
    ds.to_netcdf(args.outfile)
    

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=__doc__,
                                     argument_default=argparse.SUPPRESS,
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
                                     
    parser.add_argument("infile", type=str, help="Input txt file")
    parser.add_argument("baseline_temperature", type=float, help="Baseline to add to anomaly data")
    parser.add_argument("source", type=str, help="URL for data download source")
    parser.add_argument("outfile", type=str, help="Output netCDF file")

    args = parser.parse_args()
    main(args)