Art or Science?

Explain the thermal transfers of energy within oceans and the importance of oceanic conveyor belts.

What is the role of oceans and winds? One of the reasons why the Earth is habitable is that oceans and winds help to distribute heat between its warmest and coldest parts. Winds blowing across the sea transport heat through the atmosphere and drive ocean currents towards the poles.

The thermohaline circulation (THC) model (oceanic conveyor belt) Add the following labels onto your THC diagram: Warm salty surface ocean water of the gulf stream (Caribbean) Flows across the Atlantic to the Western coast of Europe – when it reaches the cold polar conditions in the N.Atlantic the water becomes cold and increases in density. The chilled surface water sinks in the N.Atlantic and then flows south near the bottom of the ocean (deep ocean current) towards Antarctica. In Antarctica it is cooled even more and flows north into the Indian and Pacific ocean basins. As it is approaching these more tropical regions, the water warms and becomes less dense and rises to the surface. It then returns as surface flow to the North Atlantic Ocean. It takes water almost 1,000 years to move through the entire cycle of the THC.

How does the thermohaline circulation work? In the far North Atlantic, the water is both cold and very saline (salty), which makes it denser, heavier and causes it to sink. By sinking it draws warmer water in from the ocean surface above. This in turn, draws water across the ocean surface from the Tropics. Eventually, this movement up from the Tropics draws cold water up from the ocean floor ready to be warmed again.

Why is the THC so important? It allows for the global transfer of 1.Energy – in the form of heat. It moves heat from the tropics to the poles (therefore controlling the amount of sea ice). 2.Nutrients – at great depths the water becomes enriched with many nutrients such as phosphates, nitrates, silicates and dissolved CO2.

How do ocean currents affect the UK’s climate? The current of warm water in the Atlantic is known as the Gulf Stream – its northern part is the North Atlantic Drift, which flows north past the west coast of the UK and so makes the UK’s climate warmer than it would otherwise be for its latitude. As the ocean water cools in the far North Atlantic, it becomes denser and sinks to the ocean floor. This helps to form an ocean circulation called the thermohaline circulation (global conveyor belt).

How is the thermohaline circulation being disturbed? More fresh water is entering the Arctic Ocean as a result of global warming (from ice and snow melt and normally frozen rivers not freezing). This freshwater lowers the salinity, which decreases the density of the oceans, and slows down the rate at which the ocean water sinks. This affects the global conveyor belt. Some scientists believe that global warming could turn off the North Atlantic Drift which supplies Europe with warm water and air. Winter temperature may drop by 5 ° C. Watch the inconvenient truth (46m-49m)

Annotate your map to show (1) global variations in sea surface temperatures (2) the impact of ocean currents (look at the differences on the East and West sides of the continents)

Task -What relationship is there?

Explain the thermal transfers of energy within oceans and the importance of oceanic conveyor belts.