The Gulf Stream

North Atlantic Gyre: The Gulf Steam

• Gyres are large-scale circulation patterns that develop in the surface waters in each hemisphere; they include many of the major ocean currents (such as the Gulf Stream).  

• In the northern hemisphere, gyres circulate clockwise; in the southern hemisphere, they circulate counter-clockwise. 

• Gyres develop and remain in motion as a result of Prevailing wind patterns Coriolis effect Gravity  • Most gyre circulation occurs in the top few hundred

meters of the water column, although some circulation is maintained to a depth of a thousand meters or so.

• The Gulf Stream carries salt and water into the high latitude North Atlantic where the water cools.

• The cooling and the added salt cause the waters to sink in the Norwegian Sea.

So, how does it all work again?

• Tropical Atlantic is very salty• Gulf Stream moves this water north• Water cools along the way• By the time it reaches the area between

Iceland and Europe, it has cooled enough to become very dense

• Surface water sinks to the bottom, feeding deep current – thermohaline circulation

Other “Causes” of the Gulf Stream

• The Gulf Stream is mainly caused by wind as it creates friction when moving over the water.

• This friction then forces the water to move in the same direction.

• The presence of land along the Gulf Stream’s edges also aids in its movement.

Cool Facts

• The Gulf Stream system is powerful enough to be readily seen from space

• The width of the current is about 100-200 km.

Affecting Temperature• Currents affect the global climate and weather

patterns because they distribute heat.• Keeps sea surface temperatures warm, causing

the areas around it to be warm and more hospitable; which is why Florida is warm all year round.

• Helps keep places like Ireland and England much warmer than they would otherwise be at such a high latitude.

• The Gulf Stream and its warm winds are also responsible for keeping northern Norway’s coast free of ice and snow.

Halifax, Canada Bordeaux, France

Latitude: 44.53N Latitude: 44.50N  

Longitude: 063.31W Longitude: 000.42W

 Month Avg. Temp. °C

Halifax

Avg. Temp.°C

Bordeaux

January -5 6

February -5 7

March -1 9

June 15 18

July 18 20

August 18 20

Other Results

• Winds and water temperatures in the South Atlantic (off the coast of Africa) cause Hurricanes in North America

• Changes in the direction of Ocean currents in the Pacific cause weather events like El Nino.

• El Nino - (El Nee-nyo) is the warming of water in the Pacific Ocean.

• La Nina - (Lah Nee-Nyah) is the cooling of water in the Pacific Ocean.

El Nino La Nina

Rain and flooding along the Pacific coast Warm water disrupts food chain of fish, birds, and sea mammals Tornadoes and thunderstorms in southern US Fewer than normal hurricanes in the Atlantic

Snow and rain on the west coast Unusually cold weather in Alaska Unusually warm weather in the rest of the USA Drought in the southwest Higher than normal number of hurricanes in the Atlantic

• http://www.youtube.com/watch?v=rR5TFWNLtOc