sentence2_structure: Upwelling<>is<>the term for when deep ocean water rises to the surface$$$deep ocean water<>rises<>to the surface
sentence1: Upwelling The movement of nutrient-rich deep sea water to the ocean's surface.
sentence2: Upwelling is the term for when deep ocean water rises to the surface.
question: What is the term for when deep ocean water rises to the surface?