pb5.py

fig, axarr = plt.subplots(nrows=3, figsize=[10,12], sharex=True)
for ax, var, cmap in zip(
    axarr.flat,
    ['thetao', 'so', 'cfc11'],
    [cmo.thermal, cmo.haline, cmo.matter]
):
    
    kwargs = dict(yincrease=False, x='lat', y='lev', ax=ax)
    
    # Plot a section along the dateline in 1980 in the southern ocean
    ds_section[var].plot.contourf(
       levels=31, robust=True, cmap=cmap, **kwargs
    )
    # contour the density levels
    ds_section.sigma_0.plot.contour(
        levels=np.arange(24.2,29, 0.4), colors='w', **kwargs
    )
    ax.set_title('')
# add a bit more space between the panels
fig.subplots_adjust(hspace=0.2)