As per National Aeronautics and Space Administration (NASA) research scientists found that concentrations of mercury near the ground level had increased in the Arctic Sea by mercurypumping reaction which takes place because -
1. of open water in a lead is much warmer than the air above it.
2. of the temperature difference, the air above the lead churns like the air above a boiling pot.
3. the mixing is so strong that it actually pulls down mercury from a higher layer of the atmosphere to near the surface.

Options

A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. All of the above

Answer

D

Explanation

Almost all of the mercury in the Arctic atmosphere is transported there in gaseous form from sources in areas farther south, from sources such as wildfires, coal burning and gold mining. Scientists have long known that mercury in the air near ground level undergoes complex chemical reactions that deposit the element on the surface.
Once the mercury is completely removed from the air, these reactions stop. However, this newly discovered mixing ice forces down additional mercury to restart and sustains the reactions.