What is indicated by a 'normal year' in oceanographic terms?

In oceanographic terms, a 'normal year' is typically indicated by the presence of an upwelling of cold, nutrient-rich water along the coast. This process occurs when winds blow across the ocean surface, pushing warmer surface waters away from the coast and allowing the denser, cooler, and nutrient-dense water from the depths to rise to the surface. This upwelling is vital for marine ecosystems because it supports high productivity, particularly in areas like coastal fisheries where nutrients are essential for the growth of phytoplankton, which serve as the foundation of the marine food web.

In the context of oceanic and atmospheric conditions, such as those influenced by phenomena like El Niño or La Niña, a normal year reflects a stable climate pattern where these beneficial conditions prevail, resulting in a healthy and productive marine environment. Other options mentioned, such as abnormal warm waters or stagnant water flow, would indicate deviations from this normal state, typically linked to disruptions in the typical upwelling processes critical to marine life and ecosystem health.