fv9 - el nino and la nina

AP Environmental Science: Unit 4 – Earth Systems & Resources

Topic: 4.9 El Niño and La Niña

Page 1: El Niño

  • Definition:

    • El Niño is a warming of the Pacific Ocean between South America and Papua New Guinea.

  • Causes:

    • Occurs when trade winds weaken.

    • Results in warmer waters along the west coast of South America.

  • Thermocline Effects:

    • The thermocline moves deeper, allowing more warm ocean water.

  • Weather Impacts:

    • Increased precipitation in drier climates on the West Coast.

    • Colder winters in the southeastern United States.

Page 2: La Niña

  • Definition:

    • La Niña is a cooling of the Pacific Ocean between Papua New Guinea and South America.

  • Causes:

    • Initiated by stronger trade winds.

    • Pushes warm coastal water away from South America.

  • Thermocline Effects:

    • The thermocline moves up, resulting in cooler ocean temperatures.

  • Weather Impacts:

    • Cooler temperatures and wet conditions in many areas.

    • Warmer and drier conditions in the southeastern United States.

Greater Environmental Impacts

  • Species and Ecosystems:

    • Rapid climate changes can force species to relocate or adapt.

    • Breeding seasons for birds may shift.

  • Global Climate Effects:

    • Decreased ocean heat capacity affects energy absorption, contributing to global warming.

  • Weather Variability:

    • Temperature changes influence precipitation patterns, leading to flooding or drought.

Page 3: Key Terms to Review

  • Climate Change:

    • Long-term shifts in temperature and weather patterns, primarily due to human activities.

  • Drought:

    • Prolonged low precipitation leading to water scarcity.

  • El Niño:

    • Climate pattern with warmer-than-normal ocean temperatures in the equatorial Pacific.

  • Flooding:

    • Submersion of areas due to excessive water, causing damage and ecosystem disruption.

  • La Niña:

    • Climate pattern with unusually cool surface waters in the Pacific.

  • Migration:

    • Movement of populations due to environmental changes or resource availability.

Thermocline Dynamics

  • Behavior During El Niño:

    • The thermocline deepens in the eastern Pacific.

  • Behavior During La Niña:

    • The thermocline steepens in the western Pacific.

Page 4: Additional Concepts

  • Ocean Heat Capacity:

    • Refers to the ocean's ability to absorb heat without significant temperature change.

  • Thermocline:

    • A layer in water bodies where temperature changes rapidly with depth.

  • Upwelling:

    • The process where cold, nutrient-rich water rises to the surface, supporting marine life.