def _rename_time_index(dict_da):
    """Rename the dim time of each datarray to ensure proper merge.
    Each time dim is associated to its probe.

    Parameters
    ----------
    dict_da : a dictionary of timeserie datarray

    Return
    ------
    new_dict : dict
        A dictionary of renamed DataArray
    """
    new_dict = {}
    for i, (key, xr_da) in enumerate(dict_da.items()):
        renamed_xr_da = xr_da.rename({'time': 'time{}'.format(i+1)})
        new_dict[key] = renamed_xr_da
    return new_dict