sentence2_structure: Upwelling<>is<>the term for when deep ocean water rises to the surface$$$deep ocean water<>rises<>to the surface
sentence1: For example, HABs in Spain and California might be linked to a physical ocean process called upwelling (when deep ocean water comes up to the surface near the coast of a continent).
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?