The figure below shows the formation and sinking of dense water in the Arctic Ocean between Greenland and northwest Europe. Why
is there an increased density of surface waters in this region? A. Evaporation decreases salinity, and heavy polar air increases atmospheric pressure.
B. Evaporation decreases salinity, and cool atmospheric temperatures decrease water temperature.
C. Formation of sea ice increases salinity, and heavy polar air increases atmospheric pressure.
D. Formation of sea ice increases salinity, and cool atmospheric temperatures decrease water temperature.
Answer: The correct option is A. Evaporation decreases salinity, and heavy polar air increases atmospheric pressure.
The ocean circulation conveyor belt or the thermohaline circulation of sea water that circulates massive water currents from northern to southern oceans and again back. The warm water on releasing heat becomes denser and sinks down. This closed circulation loop makes the cold water move towards the tropical region at the deeper levels.
The decrease in salinity results due to evaporation. The density of sea water depends on pressure, temperature and salinity. Density increases when temperature decreases and salinity increases. The wind field pattern is formed from the warm ascending air from the low atmospheric pressure in tropical region and high atmospheric pressure from the cool descending air in subtropical region.
In the Arctic region dense sinking surface water is counteracted by the release of fresh water due to melting of ice and a high atmospheric pressure. The low temperature in the polar region makes the air heavy and is forced to descend which causes high pressure zone.
The proteins in plasma include the antibody proteins, coagulation factors, and the proteins albumin and fibrinogen which maintain serum osmotic pressure.
These organisms should be adapted to live in this enviroment, i.e., they need to have adaptations to breathe, to swim (fins), streamlined bodies to move through the water, to eat the food found in the region, etc. Moreover, in this environment, the diversity tends to be high because marine regions are often characterized by their richness.
C. Ice is less dense than water which means water condenses when it freezes allowing the ice in a lake to float on top of the water preventing the water below from freezing.
