Weather Explainers

Weather Words: Gulf Stream

The Gulf Stream is a warm current of water that travels from the tropical Atlantic in the Caribbean to the North Atlantic near Iceland.

What Is The Gulf Stream?

While many associate the Gulf Stream with the movie, The Day After Tomorrow, the Gulf Stream is in fact an important part of Earth's climate system and is responsible for Western Europe’s mild winters compared to other locations at the same latitude.

The Gulf Stream has its beginnings in the Caribbean Sea. In the Caribbean Sea, intense sunlight heats up the water. This warm water then traverses the strait between Jamaica and Cuba, forming a horseshoe as it approaches the Florida Keys. This horseshoe is known as the Loop Current. Once the warm water passes through the Florida Keys, it becomes officially known as the Gulf Stream.

How Does The Gulf Stream Function?

After passing the Florida Keys, the Gulf Stream parallels the Southeast U.S. coast, splitting the difference between Cape Hatteras, North Carolina and Bermuda. After passing Bermuda, the Gulf Stream continues its northeastern trajectory before eventually ending up between the British Isles and Ireland. At this point, the Gulf Stream dissipates much of its heat to its surroundings, becoming cold and salty.

This cold salty water becomes denser than the surrounding ocean, sinking as the ocean equivalent of massive waterfalls. These sinking plumes of dense, salty water eventually reach the bottom of the ocean, moving back towards the tropics, thus perpetuating the cycle of warm water moving north.

As the climate warms, scientists fear that the Gulf Stream will weaken due to the introduction of freshwater from melting ice into the system of sinking dense, salty water that powers the Gulf Stream. While the Gulf Stream would likely not completely collapse in this scenario, it would likely move further south, weakening in the process. As a result, less heat would be transported from the tropics northward, causing Europe to experience much colder winters compared to today.

Hayden Marshall is a meteorologist intern and First-Year-Master’s Student at the Georgia Institute of Technology. He has been following weather content over the past three years as a Storm Spotter and weather enthusiast. He can be found on Instagram and Linkedin.