Ocean Currents and the Conveyor Belt
Lesson notes
Overview
Wind and density differences drive a global circulation of heat through the oceans. This topic is rated intermediate and is number 21 of 98 in Earth & Space. Builds on the basics with relationships, methods and trade-offs.
What you are seeing
The panel above shows the steps of a process, laid out in order. Click a step to see what happens next. The animation is drawn live from the model, so everything you see responds to the sliders. Press Space to pause, use Restart to replay from the start, and change the speed to slow down quick events.
In depth
Surface currents are driven by winds, and deep water movement is driven by differences in density, which depend on temperature and salinity, the thermohaline circulation. Cold salty water sinks in the North Atlantic and flows at depth, to resurface in the Indian and Pacific oceans after centuries, carrying heat and nutrients around the globe. The Gulf Stream keeps north-west Europe milder than its latitude suggests. Melting ice might weaken the circulation.
Reading the relationship
The expression "thermohaline circulation" is a compact summary of the idea. It uses the symbols t, h, e, r, m, o; name what each one stands for before you start. Then use the sliders to see how changing one quantity changes the others.
A guided exploration
1. Run the animation once with the default settings and describe in words what happens. 2. Change one slider at a time and note which quantity responds most. 3. Push each slider to its extreme and decide whether the result still makes sense.
Try this
Predict the outcome first, then test extreme slider values to find where the pattern changes or breaks.
Common pitfalls
Earth and space systems work on very different scales of time and distance. Check which scale a number refers to before comparing it with another.
How it connects
It builds on “Global Wind Circulation”, the topic before it in Earth & Space. Once you are comfortable, continue with “El Niño and La Niña”.
Why it matters
Earth and space science helps us understand our planet, its climate and the wider universe.
Where you might use it
- Revising “Ocean Currents and the Conveyor Belt” before a class, exam or certification
- Forecasting weather and understanding climate records and their uncertainty
- Planning for earthquakes, floods and other natural hazards in cities
- Interpreting satellite images, space missions and the age of rocks and stars
Frequently asked questions
What is Ocean Currents and the Conveyor Belt?
Wind and density differences drive a global circulation of heat through the oceans. It is an intermediate topic in Earth & Space.
How do I use the Ocean Currents and the Conveyor Belt simulation?
The panel at the top shows the steps of a process, laid out in order. Click a step to see what happens next. Move the sliders one at a time, then press Space to pause the animation and look closer.
What does the formula mean?
The expression thermohaline circulation packs the idea into symbols. Name each symbol first, then change one quantity with the sliders and see which others respond.
Who is this topic for?
Builds on the basics with relationships, methods and trade-offs. If the quiz feels hard, reread the lesson notes and try the previous topic first.
What should I learn before this?
Start with “Global Wind Circulation”, the previous topic in Earth & Space. Each topic in a subject builds on the ones before it.
How do I track my progress?
Press “Mark as learned” on this page. Progress is stored only in this browser and is never sent anywhere. The Browse page can show topics you have learned or still need to learn.
Quick quiz
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