diff --git a/doc/jupyter/Demo/Demo_9b_seaIce_data_explore.ipynb b/doc/jupyter/Demo/Demo_9b_seaIce_data_explore.ipynb
index 0cc691312..a3c3004e8 100644
--- a/doc/jupyter/Demo/Demo_9b_seaIce_data_explore.ipynb
+++ b/doc/jupyter/Demo/Demo_9b_seaIce_data_explore.ipynb
@@ -1729,7 +1729,7 @@
     "\n",
     "p = ds['siconc'].sel(time = ds.time.dt.year.isin(years_to_show)).plot(x='lon', y='lat', \n",
     "                                                                 transform=ccrs.PlateCarree(),\n",
-    "                                                                 aspect=ds.dims[\"lon\"] / ds.dims[\"lat\"],  # for a sensible figsize\n",
+    "                                                                 aspect=ds.sizes[\"lon\"] / ds.sizes[\"lat\"],  # for a sensible figsize\n",
     "                                                                 subplot_kws={\"projection\": proj_plot},\n",
     "                                                                 col='time', col_wrap=6, robust=True, cmap='Blues_r', zorder=3)\n",
     "\n",
@@ -1783,7 +1783,7 @@
     "\n",
     "p = ds['siconc'].sel(time = ds.time.dt.year.isin(years_to_show)).plot(x='lon', y='lat', \n",
     "                                                                 transform=ccrs.PlateCarree(),\n",
-    "                                                                 aspect=ds.dims[\"lon\"] / ds.dims[\"lat\"],  # for a sensible figsize\n",
+    "                                                                 aspect=ds.sizes[\"lon\"] / ds.sizes[\"lat\"],  # for a sensible figsize\n",
     "                                                                 subplot_kws={\"projection\": proj_plot},\n",
     "                                                                 col='time', col_wrap=6, robust=True, cmap='Blues_r', zorder=3)\n",
     "\n",