During strong El Niño phases, which mechanism increases nutrient stratification influencing marine ecosystems off Peru?

💡 Explanation

During strong El Niño events, trade winds weaken, suppressing the Humboldt Current upwelling because the thermocline deepens, reducing nutrient supply to surface waters and increasing stratification. Therefore weakened upwelling results, rather than increased erosion or enhanced mixing which depend on different wind patterns or thermocline depths.

• Which modification to the Walker circulation in the Pacific Ocean initiates an El Niño event?
• Which mechanism causes coastal dune formation along lake shorelines with strong prevailing winds?
• Which mechanism causes localized crustal uplift when fluids are released during subduction?
• Which mechanism causes levee breaching when prolonged rainfall saturates the levee structure?
• Which process drives the upward transport of silica-rich magma at strike-slip fault zones?
• Which erosional mechanism primarily shapes the steep U-shaped valleys characteristic of Norwegian fjords?