Which mechanism is disrupted by El Niño events, causing widespread marine ecosystem effects?

💡 Explanation

During El Niño, weakened trade winds reduce coastal upwelling because the normal pressure gradient diminishes, suppressing the upwelling of cold, nutrient-rich waters. Therefore, disruption of coastal upwelling occurs, rather than affecting polar ice, geothermal activity, or tidal phenomena which operate independently of El Niño.

• Which mechanism significantly influences the prevailing wind direction in mid-latitude cyclones due to the Coriolis effect?
• Which mechanism amplifies stream incision when tectonic uplift occurs in a humid region?
• Which mechanism increases risks associated with lava dome destabilization?
• Which outcome results when interseismic stress exceeds frictional strength along a subduction zone megathrust fault?
• Which outcome is worsened by thermocline breakdown during upwelling?
• Which risk greatly increases when excessive groundwater extraction collapses subterranean karst systems?