Oceanic circulation Flashcards
What is/ what is the purpose of oceanic circulation?
The oceans move surplus energy from the equator to the poles
Warm water moves from the equator towards the poles, while colder water moves from the poles to the equator
Currents follow loops or gyres in a clockwise direction in the northern hemisphere
North Atlantic Gyre (1)
In the Atlantic Ocean, warm water originates in the Gulf of Mexico, and travels North-East, past the USA in the GULF STREAM, and then on to the NORTHERN ATLANTIC DRIFT, towards the Atlantic Ocean
North Atlantic Gyre (2)
Once the water reaches the UK/Ireland, it splits and half travels Northwards in the NORWEGIAN CURRENT (warmer water) and half travels past the West of Spain and Africa as the cooler CANARY CURRENT, travelling southwards
North Atlantic Gyre (3)
The water then travels westwards as the NORTH EQUATORIAL CURRENT and returns back to the Gulf of Mexico
Factors affecting oceanic circulation/North Atlantic Gyre
Prevailing winds
Coriolis force
Land masses
Temperature difference
Factors affecting oceanic circulation/North Atlantic Gyre
Prevailing Winds
Surface ocean currents directly respond to prevailing winds due to surface friction
e.g. the Westerlies in the Atlantic help direct the gulf stream and the North Atlantic Drift
Factors affecting oceanic circulation/North Atlantic Gyre
Coriolis force
This deflects the currents RIGHT in the northern hemisphere, and LEFT in the southern hemisphere
Factors affecting oceanic circulation/North Atlantic Gyre
Land masses
Currents are blocked and deflected by continental landmasses setting up roughly circular loops or gyres - gyres move clockworks in the northern hemisphere
Factors affecting oceanic circulation/North Atlantic Gyre
Temperature differences
Cold water is denser and therefore sinks, and travels towards the equator
Warm water is less dense so rises to the surface and flows away from the equator - a convection cell is created
