What is the Gulf Stream?
Quick answer
The Gulf Stream is a powerful, warm ocean current that flows from the Gulf of Mexico up the US East Coast and across the Atlantic. Its extension, the North Atlantic Drift, carries warm water toward northwestern Europe, helping keep places like the UK, Ireland and Norway milder than other regions at the same latitude.
A river in the ocean
| Speed | Up to about 2.5 m/s (5.6 mph) near Florida |
| Width | About 100 km |
| Flow | Many times the combined flow of all the world’s rivers |
| Water temperature | Often 5–10°C warmer than the surrounding sea |
How it warms Europe
London is farther north than Calgary, Canada, yet London’s winters are much milder. Warm water carried north releases heat into the air, and the westerly winds blow that milder air over Europe. Scientists note that weather patterns and the wind itself also play big roles, but ocean heat is an important part.
Part of a bigger system
The Gulf Stream is part of the Atlantic Meridional Overturning Circulation (AMOC), a giant conveyor belt:
- Warm, salty surface water flows north.
- In the far North Atlantic, it cools, becomes denser and sinks.
- Cold deep water flows back south.
Could it slow down?
Melting ice from Greenland adds fresh water, which is less dense and could weaken the sinking that drives the AMOC. Studies suggest it has slowed in recent decades. Scientists debate how quickly, and whether a major collapse could happen this century. Such a change could bring colder winters to northwestern Europe and shift rainfall patterns worldwide.
Gulf Stream history
Benjamin Franklin published one of the first charts of the Gulf Stream in the 1770s, noticing that ships sailing to Europe with the current crossed faster than those coming back against it. He also coined the phrase in well done is better than well said.
For more ocean facts, see why the ocean is important. Cold Arctic air can also reach Europe through the polar vortex.
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