6.2A

Question 1

Oceanic sequestration

Answer 1

• The ocean is one of the largest Carbon in store being 50 times greater.
• There is a significant input of both organic carbon and carbonate ions from continental rive run-off.

Question 2

Biological Pump

Answer 2

-Carbonate pump involving thermohaline circulation.

Question 3

Thermohaline

Answer 3

-The water in these circuits transport energy (in the form of heat) and mass (dissolved solids and gases).

Question 4

Carbonate pump being a physical pump

Answer 4

-This circulation is part of a third important process call the physical pump which pump CO2 from the surface from the surface of the ocean to the deep ocean.

Question 5

Carbonate pump explained

Answer 5

• Relies on inorganic Carbon sedimentation.
• Marine Carbons may utilise calcium Carbonate (CaCO3)
• When organisms die and sink, many shells dissolve before reaching the sea floor sentiments which leads to the carbon becomes part of deep ocean currents.
• Shells that do not dissolve build up slowly in the sea floor, forming limestone sediments.

Question 6

Physical pump

Answer 6

• Oceanic circulation fo water involving upwelling, downwelling and thermohaline current.
• CO2 in the oceans is mixed much more slowly that in the atmosphere.
• The colder the water the more the CO2 gets stored (10% more in deeper water).
• More than twice as much of Carbon can be dissolved in polar rather than in warmer waters.
• Warmer waters release more CO2 into the atmosphere.
• Cooler water water has a higher density making CO2 sink.

Question 7

Biological pump

Answer 7

• Organic sequestration of CO2 by phytoplankton.
• Microscopic organisms grow near the surface of the water to photosynthesise and are the marine food web (half of earth’s biomass).
• Carbon is then passed up to the food chain by consumer dust and zooplankton which release CO2 back into the water and atmosphere.
• The flux between the atmosphere and ocean is 11 gigatonnes per year.