Question

At which location would sunlight have to pass through the thickest amount of atmosphere before reaching Earth's surface

Answer 1

Stratosphere

The ozone layer protects life on earth by absorbing harmful ultraviolet radiation. The ozone layer is located between seventeen kilometers and thirty-five kilometers above the earth's surface in the stratosphere (2). The ozone layer is also known as the earth's shield. This layer contains high concentrations of ozone. It is interesting to note that Ozone is made up of three oxygen molecules; water consists of one hydrogen molecule and two oxygen molecules. It absorbs about ninety-seven percent of the sun's ultraviolet rays. 

Answer 2

Answer:

At the equator

Explanation:

The thickness and depth of the atmosphere on earth varies from one geographic location  to the other. This thickness not only vary with location but also with time of year.

Equator is warmer than any other part of the world and hence the air mass over the equator is, on average, warmer there than anywhere else on Earth.  Cold air is denser than warm air . However the gravitational force is exerted in equal amount across the world , therefore , the same amount of air molecules over the equator go upward while  the air molecules in the coldest regions on Earth i.e the poles hovers near the surface of earth . Thus, the atmosphere is thickest and deepest at the equator.