Labs / Geography
Ocean Currents & Gyres
Surface winds and the Coriolis effect stir the ocean into great rotating gyres, with fast warm currents on their western edges and cold ones on the east. Click anywhere to drop a drifter and watch it ride the flow, then switch to the deep view to see the thermohaline conveyor that temperature and salinity power. Nudge the sliders and the whole basin responds.
speed —flow —gyres N ↻ / S ↺drifter click to drop
What to try
- Drop a drifter on the far western edge of a gyre. Why does it race poleward there but crawl along the eastern side?
- Compare the northern and southern subtropical gyres. Why do they spin in opposite directions even though the same winds blow?
- Slide the equator-to-pole temperature difference down toward zero. What happens to the strength of the currents, and what would that mean for a sailor?
- Switch to the deep conveyor and raise the salinity. Where does water sink, and how many Sverdrups does the overturning reach?
- Set the winds to "Calm" and release a drifter — how far does it travel in a year compared with the "Global belts" pattern?