CBSE Class 10 Answered

The ozone depleting mate?r?i?a?l?s??????? ??(?i?n? ?t?h?e?? (in the form of source? ?gases and some reactive products) enter the stratosphere primarily?? ?from the tropical upper troposphere. Stratospheric air?? ?motions then transport these gases upward and toward the?? ?pole in both hemispheres.

The severe depletion of the Antarctic ozone layer known as the “ozone hole” occurs ?because of the special atmospheric and chemical conditions that exist there and nowhere else on the globe. The very low ? ?winter temperatures in the Antarctic stratosphere cause polar stratospheric clouds (PSCs) to form. Special reactions that ?occur on PSCs, combined with the relative isolation of polar stratospheric air, allow chlorine and bromine reactions to produce the ozone hole in Antarctic springtime.

(The formation of the Antarctic ozone hole requires temperatures low enough to form polar stratospheric clouds (PSCs), isolation from air in other stratospheric regions, and sunlight.?)