Ocean Currents and Global Heat
Explain thermohaline circulation (the global conveyor belt) as driven by temperature and salinity differences that cause dense water to sink; describe how the Atlantic Meridional Overturning Circulation (AMOC) transfers heat from the tropics toward Europe; explain that oceans absorb more than 90% of excess heat and ~25% of CO2 from human emissions; explore what would happen to Northern European climates if circulation weakened
Lesson
Set out your lesson
“Thermohaline means temperature-and-salinity related. At comparable pressure, colder or saltier seawater is generally denser. The AMOC carries warm upper water north and colder deeper water south in the Atlantic. Winds and mixing also matter. This model is not a single pipe followed by all water. Safety: No water, salt, glass containers, heat sources or weather exposure. Stop: Stop with the paper model. No saltwater, heating, cooling or density experiment is required.”
Bring to the table
- Paper
- Pencil
Extra for the adult
Worked example. B is denser than A because it is colder at the same salinity and pressure. C is less dense than B because it is fresher at the same temperature and pressure. More freshwater could weaken sinking, but these cards cannot calculate a real current speed or regional temperature.
Optional challenge. Why can reduced heat transport and global warming occur at the same time? Adult key: Greenhouse forcing can warm the globe while changed transport reduces warming or causes cooling in a particular region relative to its comparison case.
What to notice. Keep the arrows and budget notes. Record adult help separating temperature, salinity and heat transport.
Share and support
Family records and proof options
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Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
NOAA · Practice link — not the full lesson
Ocean and coasts
Before you open · source notes
Ocean and coasts supports Ocean Currents and Global Heat. An adult previews and guides; this is a learning page, not a scored quiz.
Free educational page, no sign-in required for the tested path.
Before you openAsk the learner one fact they learned and one question they still have.
Opening this link does not save learning or assess mastery.
Source, access and review notes
Public NOAA page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.
NOAA. “Ocean and coasts.” External page; Gakuva does not copy, host, embed, or redistribute materials.
Unknown — link only
Check understanding
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“Can your child explain why the UK has mild winters compared to parts of Canada at similar latitudes — what does ocean circulation have to do with it, and what might change if that circulation slows down?”
Curriculum record
- Type
- Conceptual
- Subject
- Science
- Domain
- Ocean Life
- Age range
- Ages 11–12