Ocean currents, Upwelling and El Nino

Chapter 2 Earth Processes Day#6. Lesson plan

2.3 Tides and ocean currents-cont.
- describe the formation of ocean currents and upwelling
- explain the formation of the global ocean conveyor belt and its importance
- discuss the causes and effects of El Niño and La Niña events during the El Niño Southern Oscillation (ENSO) cycle in the Pacific Ocean

Current: a continuous physical movement of water caused by wind or density
Coriolis effect: a force that results from the Earth’s rotation that causes objects or particles in motion to deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
Thermohaline circulation: large-scale ocean circulation caused by density differences due to temperature and salinity changes in the world’s ocean
Global ocean conveyor belt: constantly moving systems of deep-ocean water driven by thermohaline circulation
Downwelling: the downward movement of water in the sea due to density differences
Upwelling: the movement of cold, nutrient-rich water from deep in the ocean to the surface
El Niño: a warm current that develops off the coast of Ecuador around December, which can cause widespread death within local food chains
La Niña: a cold current that develops off the coast of Ecuador and spreads across the Pacific, reducing sea surface temperatures for extended periods of time
Humboldt Current: a cold water current with low salinity levels that flows north along the western coast of South America; also called the Peru current

Lecture/Notes (PPT – slides 51 – 60)
- this lesson covers the major type of currents: surface and seep currents
- Simplify the concept:
  - break down the formation of the global ocean conveyor belt into simple steps, emphasizing how cold, salty water sinks in the polar regions and how warm water rises in the tropics;
  - create flowcharts that outline the process and the different components of the conveyor belt, such as the thermohaline circulation (see PPT).
  - Explain how the global ocean conveyor belt helps regulate Earth’s climate by redistributing heat.
  - Discuss how this system transports nutrients and supports marine ecosystems by facilitating upwelling in certain areas.
- this lesson also covers the causes and effects of El Nino and La Nina.
  - Show documentary clips or animations that explain the ENSO cycle, highlighting the differences between El Niño and La Niña.

Lecture/Notes (PPT – slides 51 – 60)
- this lesson also covers the causes and effects of El Nino and La Nina.
- Show documentary clips or animations that explain the ENSO cycle, highlighting the differences between El Niño and La Niña.
- Facilitate group discussions where students analyze the causes of ENSO events and predict their potential impacts on global climate.

CREDIT: usoceangov

Small group activity – Practice Questions (PPT – slides 61 – 62)
- Project AICE style questions.
- Set a time limit for each question or section to simulate exam conditions (e.g., 1-2 minutes per mark).
- Encourage students to read each question carefully, annotate key points, and plan their answers.
- Allow students to work in pairs to answer the questions.
- Monitor progress and provide support as needed, clarifying any misunderstandings or offering hints to guide students in the right direction.
- Encourage students to compare their answers with the model answers provided.

CREDIT: Hakai Institute

Discuss the importance of upwelling and the correlation between El Nino and upwelling.

Exit ticket
- If you opt to have students complete their notes using the Student Guided Notes format during your lecture, then use the bellringer as the exit ticket activity in class.
- If you opt to have students complete their notes using the Student Guided Notes format at home (homework), then use the following exit ticket activity:
  - Question 7 page 58 (Coursebook)