Chapter 22, Problem 76A

Interpretation Introduction

Interpretation:

The reason for the concentration of ozone over Antarctica to decrease about the same time every year needs to be explained.

Concept introduction:

Ozone is known to be a protective layer in the stratosphere. This layer helps the atmosphere to get exposed to harmful UV rays of the sun. Ozone is O₃ molecules.

Explanation of Solution

The depletion of the Antarctic ozone layer is known as ozone hold which takes place due to chemical and special atmospheric conditions present there which is not there anywhere else on the globe. In the Antarctic stratosphere, there are very low winter temperatures which results in the formation of polar stratospheric clouds or PSCs. This causes ozone hole and it occurs every year in Antarctica between September and November months as it is string time for South Pole. During this time, most of the ozone level over Antarctica is reduced to approximately 60% of the usual value.