Question

in a paragraph, What role does the Great Ocean Conveyor Belt or thermohaline circulation play in the carbon cycle? Describe how it works to store carbon and its importance. What risks do melting continental glaciers present to this function? Why?

Answer 1

Great ocean conveyor belt is the movement of seawater across the oceans of the world. This movement is driven by the difference in the density of the layers of water in the ocean. The upper layer of water in ocean at poles is cooler due to cooler climate at the poles and so it is highly dense while upper layer of oceans at equator is warmer due to high incoming sunlight and hence it is the less denser one. The cooler water from the poles sinks at the bottom and move towards equator. Water at equator makes way for the water coming from poles by moving it's less dense water towards poles and thus amount of water also remains balanced. This is called as great ocean conveyor belt.

The movement of waters caused the nutrients in it to mix up well in oceans across the world.carbon absorbed in the upper layer us thus circulated very well in the oceans.

Also the carbon dioxide is used for the photosynthesis in the upper layers of ocean (euphotic zone) to produce organic matter. This carbon act as carbon sink. The ocean conveyor belt moves the organic matter to the bottom of oceans after the death of animals, plant and makes way for new organic carbon to form & sink again. Thus ocean conveyor belt continuously store the carbon at the bottom of oceans & forms a great a carbon sink. The carbon sink is very essential as it decreases the amount of carbon in the atmosphere & thus helping in cooling the global temperature and maintaining the carbon balance.

Due to high incoming sunlight at equator, continental glaciers in this area melts. Thus melted cold water from continental glaciers when meets the oceans, it makes the warm upper water of the equatorial oceans a cooler one. Thus it looses the density contrast, which causes the great ocean conveyor belt and disrupts the functioning of great ocean conveyor belt.

Addition of melted freshwater to the oceans also decreases salinity of oceans and hence the density of oceans also. This decreased density of oceans also decreases density contrast and disrupts the great ocean conveyor belt.

This disruption of great ocean conveyor belt , affects the carbon sinking and also mixing of carbon in the oceans. This leads to the increase in carbon in atmosphere and increase in global temperature.