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 causes large-scale crustal deformation when a continental plate overrides an oceanic plate at a subduction zone?
• Which failure mode arises when a heated pipeline is constructed above discontinuous permafrost?
• Which geological feature is most directly shaped by strike-slip movement along a transform fault boundary?
• Which effect increases in global coastal areas as the frequency of El Niño events rises?
• Which outcome results from eolian abrasion in deserts?
• Which mechanism accelerates coastal erosion when surface water is drawn offshore by strong winds?