def grdfiles(tile):
    subd = get_subd(tile)
    directory = dirgrid.format(subd=subd)
    filename = f'{directory}/gigatl1_grd_masked.{tile:04}.nc'
    if (not os.path.isfile(filename)):
        mount(subd, grid=True)
    return filename
def grdfiles(tile):
    subd = get_subd(tile)
    directory = dirgrid.format(subd=subd)
    filename = f'{directory}/gigatl1_grd_masked.{tile:04}.nc'
    if (not os.path.isfile(filename)):
        mount(subd, grid=True)
    return filename