Gulf Stream is a major ocean current. This swift current forms the northwestern edge of a large, clockwise system of currents in the North Atlantic Ocean. The Gulf Stream has an important effect on climate, transportation by sea, and the circulation of nutrients and wastes in the ocean.
The Gulf Stream was named by the American statesman and scientist Benjamin Franklin. Franklin thought the current started in the Gulf of Mexico. However, the Gulf Stream forms in the western Caribbean Sea. It flows through the Gulf of Mexico and the Straits of Florida. It moves north along the east coast of the United States to Cape Hatteras in North Carolina. There, it turns northeast. Part of the current later recirculates, forming a countercurrent. Other major ocean currents in the North Atlantic system include the North Equatorial Current, North Atlantic Current, and Canary Current.
Effects of the Gulf Stream.
The Gulf Stream, warmed by the hot Caribbean sun, ranges from 11 to 18 Fahrenheit degrees (6 to 10 Celsius degrees) warmer than the surrounding water. In winter, the temperature of the current east of Cape Hatteras is warmer than the air temperature. As a result, the water warms the air. The westerly winds that blow toward Europe are thus warmed as they cross the Gulf Stream. The United Kingdom, Ireland, and Norway have milder winters than other regions of the same latitude because this warm air blows over their coasts.
The swift flow of the Gulf Stream plays an important role in sea transportation. For example, navigators of ships traveling from the Panama Canal to New York City have learned to travel with the Gulf Stream and get a boost from its current.
Another important effect of the Gulf Stream is its circulation of water along the east coast of the United States. Cities and industries dump wastes into the ocean in that area. The flow of the current helps scatter and dilute the pollutants. The current, which reaches the ocean bottom, also brings nutrients from the ocean floor to the surface. This promotes the growth of aquatic organisms that live near the surface. These organisms, in turn, are eaten by various kinds of fish.
The path of the Gulf Stream,
unlike that of a river, varies somewhat from day to day. The current originates in the western Caribbean Sea as the result of westward-blowing trade winds (see Trade wind). It then flows into the Gulf of Mexico. There, it forms a large loop that may reach the mouth of the Mississippi River. As the Gulf Stream moves through the Straits of Florida, it reaches a surface speed of about 5 knots (nautical miles per hour). Its volume of flow in this area is about 1,100 million cubic feet (30 million cubic meters) of water per second. This volume is over 50 times as great as the total flow of all the world’s rivers.
The Gulf Stream travels north along the Florida and Carolina coasts. It heads northeast at Cape Hatteras. Its path becomes twisted as large swirls of warm water break off and colder water from the north sweeps southward across its route. A portion of the Gulf Stream forms a countercurrent that flows south and then west. This countercurrent rejoins the Gulf Stream on its seaward side along the Florida and Carolina coasts, adding to the volume and strength of the current.
The main part of the Gulf Stream continues northeast until it breaks up into swirling currents called eddies east of the Grand Banks, off the coast of Newfoundland. Some eddies drift toward the United Kingdom, Ireland, and Norway and form the North Atlantic Current. An even larger portion of the Gulf Stream flows south and east. The water becomes part of countercurrents that flow westward or it joins the Canary Current.
Scientists use orbiting space satellites to follow the flow of the Gulf Stream. These satellites map the temperature and color of the current’s surface patterns. Gulf Stream water is extremely clear. Its clearness makes it appear bluer than the surrounding water.
