def _populate_control(coords, year, month, day, hour, alt, meteo_dir,
    meteofiles, run, controlfname, trajname):
    """
    Initialize and write CONTROL text to file (called CONTROL).

    Parameters
    ----------
    coordinates : tuple of floats
        The parcel (latitude, longitude) launch location in decimal degrees.
    years : list of ints
        The year of the simulation
    months : list of ints
        The month of the simulation
    hours : list of ints
        Parcel launching times in UTC.
    alt : int
        The altitude (usually meters above ground level) from which
        parcel will be launched.  Must be less than model top (10000 m)
    meteo_dir : string
        Full or relative path to the location of the meteorology files.
    meteofiles : list of strings
        List of strings representing the names of the required
        meteorology files
    run : int
        Length in hours of simulation.
    controlfname : string
        The name of the control file, which should be 'CONTROL'
    trajname : string
        The intended name of the trajectory file

    """
    controltext = [year + ' {0:02} {1:02} {2:02}\n'.format(month, day, hour
        ), '1\n', """{0!s} {1!s} {2!s}
""".format(coords[0], coords[1], alt
        ), '{0!s}\n'.format(run), '0\n', '10000.0\n', '{0!s}\n'.format(len(
        meteofiles))]
    for fname in meteofiles:
        controltext.append('{0}/\n'.format(meteo_dir))
        controltext.append('{0}\n'.format(fname))
    controltext.append('./\n')
    controltext.append('{0}\n'.format(trajname))
    with open(controlfname, 'w') as control:
        control.writelines(controltext)
