Ocean circulation

Question 1

Atmospheric circulation

Answer 1

Temperature differences between land and sea create pressure gradients.

• Land and Sea breezes
• Low pressure when air is rising
• High pressure when air is falling

Question 2

Global circulation

Answer 2

Mainly due to temperature changes in air masses.

Question 3

Wind direction in relation to ocean currents (atmospheric circulation)

Answer 3

Wind direction is labelled from the bearing that it originates from. Wind blows from high too low pressure.
- Eg, westerly wind comes from the west

Question 4

Thermohaline circulation

what is it?
where does it originate from?
what are some effects of thermohaline circulation?

Answer 4

Thermohaline circulation begins in Earth’s polar regions.
- when ocean water gets very cold in these areas,
- Sea ice forms
- Surrounding seawater gets saltier, (because when sea ice is formed, the salt is left behind) - effect
- Increases in density and sinks.
Thermohaline is that layer of more dense, saltier body of water that is below the surface layer(s).

Question 5

Explain how the Ekman spiral works?

Answer 5

Wind blowing over the water creates a surface current 45 deg offset from the wind.
Each successive layer of water is moved and deflected by the layer above, creating a spiraling pattern of water movement that diminishes with depth.
- all movement in the n/h will move 45 deg to the right and left in the s/h 45 deg.

Question 6

Describe two ways that upwelling can happen?

Answer 6

1. Wind blowing across surface layer

2. Deep water currents hit an underwater obstruction