Ocean Currents – Winds, the Coriolis Effect and the Global Conveyor Belt
GeographyWater & OceansAges 15–16
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Sign in to playA world map (with an optional 3D globe) of the major surface currents flowing in gyres: warm currents (red) run poleward along the western sides of oceans, such as the Gulf Stream, Kuroshio and Agulhas; cold currents (blue) run towards the equator along the eastern sides, such as the California, Humboldt and Benguela currents. Show the prevailing winds to link trade winds and westerlies to the direction of each gyre, or switch to the deep layer to see the thermohaline conveyor belt. Drop drifting bottles and track their path, days and distance; compare January temperatures in London and St John's (Newfoundland); add meltwater to the North Atlantic and watch the conveyor weaken.
Lesson: Ocean currents and thermohaline circulation
What it shows
Surface ocean currents are driven mainly by the prevailing winds: trade winds push water west in the tropics and westerlies push it east in mid-latitudes. The Coriolis effect deflects moving water to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, and continents block the flow, so the water circulates in huge gyres. Warm currents carry heat poleward on the western sides of oceans, and cold currents flow towards the equator on the eastern sides. Deep below, cold salty water sinks near Greenland and Antarctica and drives a slow global conveyor belt.
How to use
Tick Prevailing winds to compare wind arrows with the direction of each gyre. Press Drop bottle, or tap the sea, and watch where the bottle drifts and after how many days it washes ashore; use Speed to run faster. Set Layer to the thermohaline conveyor belt to see where water sinks and rises. Drag Meltwater to the right and watch the conveyor strength and the London January temperature fall. Press 3D to spin a globe.
Parameters you can change
- Current layer shown Surface currents, Thermohaline conveyor belt (deep currents), Both
- Show prevailing winds and gyre direction
- Where the first bottle is dropped Off Florida (Atlantic Ocean), South of Japan (Pacific Ocean), Off Peru (Pacific Ocean), Mozambique Channel (Indian Ocean)
- Simulation speed 5–120 days/second
- Meltwater added to the North Atlantic 0–100 %
Questions to explore
- Why are warm currents usually found on the western sides of oceans and cold currents on the eastern sides?
- London is farther north than St John's but has much milder winters. Why?
- How might the climate of western Europe change if Greenland's ice melted quickly?
