def nemo_yyyymmdd(arrow_date):
    """Return an Arrow date as a string formatted using the NEMO forcing date convention;
    i.e. y2022m02d28.

    :param arrow_date: Date/time to format.
    :type arrow_date: :py:class:`arrow.arrow.Arrow`

    :return: Date formatted as NEMO forcing date.
    :rtype: str
    """
    return arrow_date.format("[y]YYYY[m]MM[d]DD")