Atmospheres Flashcards
Oceanic circulation
What are ocean currents?
Movements of water horizontally.
What is the primary function of ocean currents?
Transport energy from areas of strong heating to cooler areas.
What do warm currents do?
Transport warmer water from lower latitudes to higher latitudes.
What do cold currents do?
Take colder water from higher latitudes to lower latitudes.
What drives ocean currents?
Wind and thermohaline circulation interacting with each other.
How does wind affect ocean currents?
Moves the surface waters by friction.
What is the Coriolis effect?
the pattern of deflection taken by objects not firmly connected to the ground as they travel long distances around Earth.
What does ‘thermo’ refer to?
Related to heat or temperature.
What does ‘haline’ refer to?
Relating to salt or salinity.
How do temperature and salinity affect water density?
Colder water is more dense, and saltier water is more dense.
What affects the salinity of ocean water?
Precipitation, evaporation, and river runoff.
How does cold salt water behave as it approaches freezing point?
Continues to become denser down to freezing point.
Why does cold, salty surface water sink near Antarctica and Greenland?
Because it is very dense.
What causes horizontal ocean currents to flow?
Density gradients, flowing from low density to high density.
Do currents flow directly in the direction of the density gradient?
No, they flow in circular loops or gyres.
What are gyres?
Spiral oceanic surface currents found in both the Northern and Southern Hemispheres.
What direction do the main subtropical gyres flow in the Northern Hemisphere?
Clockwise.
What direction do the main subtropical gyres flow in the Southern Hemisphere?
Anti-clockwise.
Name one warm current in the north-west Atlantic.
Gulf Stream.
Name one warm current in the north-west Pacific.
Kuroshio Current.
Name one warm current in the south-west Indian Ocean.
Agulhas Current.
How does the Atlantic’s vertical circulation compare to the Pacific’s?
Stronger vertical circulation in the Atlantic.
What is unique about the Southern Ocean’s currents?
Stronger and deeper, going strongly eastwards without a poleward flow.
