fix broken link

Author: j-atkins

docs/user-guide/assignments/case_studies_virtualship.ipynb

@@ -80,7 +80,7 @@
    "source": [
     "## 5) Atlantic Meridional Overturning Circulation (AMOC)\n",
     "\n",
-    "The Atlantic Meridional Overturning Circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. The general thermohaline circulation is a pattern of water flow through the world's oceans. The AMOC consists of upper and lower cells. Observing and understanding the changes in the AMOC is critically important for identifying the mechanisms of decadal climate variability and change, and for interannual-to-decadal climate prediction. Because this is a very broad topic it would be wise to mimic one of the ongoing research programs, e.g. http://www.oceansites.org/tma/move.html."
+    "The Atlantic Meridional Overturning Circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. The general thermohaline circulation is a pattern of water flow through the world's oceans. The AMOC consists of upper and lower cells. Observing and understanding the changes in the AMOC is critically important for identifying the mechanisms of decadal climate variability and change, and for interannual-to-decadal climate prediction. Because this is a very broad topic it would be wise to mimic one of the ongoing research programs, e.g. https://www.ocean-ops.org/oceansites/tma/move.html."
    ]
   },
   {