Which process limits coastal upwelling efficiency during El Niño events?

💡 Explanation

During El Niño, weakened trade winds cause the thermocline to deepen, diminishing the upwelling of nutrient-rich deep waters because vertical mixing is suppressed. Therefore thermocline deepening restricts coastal upwelling, rather than stronger winds, surface divergence, and downwelling which exacerbate upwelling under normal conditions.

• Which mechanism redistributes surface pollutants when plastic debris concentrates within an oceanic gyre?
• Which consequence results when increased organic acid production occurs within cave stream sediments?
• Which mechanism causes the deflection of high-altitude wind streams?
• Which pedogenic outcome occurs when intense rainfall impacts bauxite deposits?
• Which outcome increases erosion in karst regions because of accelerated chemical weathering?
• Which outcome arises when an extreme flood event exceeds natural levee height along a major river?