Question

How is thermohaline circulation influenced by salinity and temperature?
a. It is driven by density gradients, which are affected by salinity and temperature, with cold water and water with higher salt concentrations being more dense.
b. It is driven by density gradients, which are affected by salinity and temperature, with warm water and water with higher salt concentrations being more dense.
c. It is driven by density gradients, which are affected by salinity and temperature, with warm water and water with lower salt concentrations being more dense.
d. It is driven by density gradients, which are affected by salinity and temperature, with cold water and water with lower salt concentrations being more dense.

Answer 1

It is driven by density gradients, which are affected by salinity and temperature, with cold water and water with higher salt concentrations being more dense.

Answer 2

Answer: d. It is driven by density gradients, which are affected by salinity and temperature, with cold water and water with lower salt concentrations being more dense.

Thermohaline circulation is the circulation in oceans which are driven by differences in the density. The word thermohaline means thermo-temperature and haline- salinity. The differences in the temperature difference arises from heating and cooling at the ocean surface, freshwater fluxes, ice formation increases the salinity, ice melting decreases salinity, precipitation also increases salinity.  

In the Earth's polar regions ocean water gets cold forming sea ice. The surrounding sea water gets saltier, it's density increases, and starts to sink. Therefore, density of cold water and water with lower salt concentrations will be more denser.