Which shift causes increased ocean upwelling along the South American coast during a La Niña event?

💡 Explanation

During a La Niña event, strengthened trade winds across the Pacific enhance the upwelling process because they push surface water offshore, allowing nutrient-rich deep ocean water to rise. Therefore increased upwelling results, rather than decreased upwelling. Humboldt current weakening or temperature elevation do not drive La Niña upwelling.

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