Oceanic currents Flashcards
What are ocean currents mainly driven by?
Prevailing surface winds and are another mechanism by which surplus heat energy in the tropics is distributed to higher latitudes
Are the ocean currents flowing towards the equator warm or cold?
They are cold flows of water moving through warmer oceans. These currents move towards the equator along the east sides of the oceans
Are the ocean currents flowing towards the poles warm or cold?
Warmer, as they originate in the equatorial zone. These currents flow towards the poles on the west sides of the oceans
What is large scale circulation driven by?
By warm water rising and cold water sinking.
What happens when ice forms in polar regions?
It forms from fresh water, leaving its salt behind to make the water even saltier and heavier.
What is the sinking of water in polar areas known as?
Thermohaline circulation - which is driven by both temperature and salinity
Summarise oceanic circulation in 6 points
1) Oceanic circulation starts with heating from the Suns energy at the equator
2) Warm waters move north and south away from the equator
3) Westerly winds help to drive the Gulf Stream on
4) As water moves poleward in ocean currents, it cools and turns to ice
5) This freezing increases the salt content, causing water to sink as it is denser
6) This creates cold deeper currents that ate cold water towards the equator
Summarise atmospheric circulation in 7 points
1) High temperatures at the Equator start the system off. Water evaporates and air rises up into the atmosphere
2) War air moves north in the Hadley cell to balance out temperature differences between equator and poles.
3) Cooler air sinks down causing high pressure at 30°C
4) This creates the deserts
5) Pressure differences create the westerlies in the Ferell cell, taking warmer air north
6) The polar cell and Ferrell cells meet, air is uplifted over the UK
7) Air migrates North in the polar cell, it chills and the air sinks down at the pole causing high pressure
What is the global ocean conveyer belt?
A constantly moving system of deep-ocean circulation, driven by temperature and salinity
What is the global ocean conveyer belts motion caused by?
The combination of thermocline currents in the deep oceans and wind driven currents on the surface
Does warm water sink or remain on the surface?
It remains on the surface, as it is less dense than cold water
Name 3 components of oceanic circulation
- Has gyres
- Involves circulating water
- Involves salinity (salt) differences
Name 6 components of both oceanic circulation and atmospheric circulation
- Has high and low pressure areas
- Driven by differences in energy between poles and equator
- Has cold and warm sections
- Needs energy from the sun to function
- Contributes to moving plastic pollution
- Westerly winds have an impact on the system
Name 3 components of atmospheric circulation
- Involves rising and falling air
- Has the Hadley cell
- Has the polar cell
