diff --git a/notebooks/wp5/satellite_sea_ice_type.ipynb b/notebooks/wp5/satellite_sea_ice_type.ipynb
index eaef87f..65eac75 100644
--- a/notebooks/wp5/satellite_sea_ice_type.ipynb
+++ b/notebooks/wp5/satellite_sea_ice_type.ipynb
@@ -167,7 +167,7 @@
     "    conc_myi = ds_nersc[\"conc_2yi\"]\n",
     "    n = 3\n",
     "    while (varname := f\"conc_{n}yi\") in ds_nersc.variables:\n",
-    "        conc_myi += ds_nersc[varname]\n",
+    "        conc_myi += ds_nersc[varname].fillna(0)\n",
     "        n += 1\n",
     "\n",
     "    if not use_fyi:\n",
@@ -491,6 +491,32 @@
     "    facet.fig.suptitle(f\"{use_ambiguous=}\")\n",
     "    plt.show()"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "19",
+   "metadata": {},
+   "source": [
+    "## Plot bias"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "20",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "with xr.set_options(keep_attrs=True):\n",
+    "    bias = (ds_cds - ds_nersc)[\"percentage\"]\n",
+    "bias.attrs[\"long_name\"] = \"Bias of\" + bias.attrs[\"long_name\"]\n",
+    "for use_ambiguous, da in bias.groupby(\"use_ambiguous\", squeeze=False):\n",
+    "    facet = plot_maps(\n",
+    "        da, cmap=cmocean.cm.balance, center=0, coastline_color=\"k\", robust=True\n",
+    "    )\n",
+    "    facet.fig.suptitle(f\"CDS - NERSC; {use_ambiguous=}\")\n",
+    "    plt.show()"
+   ]
   }
  ],
  "metadata": {