ANTARTIC OZONE HOLE (Syllabus: GS Paper 3 – Env and Eco)

Context: The Antarctic ozone hole recently reached its largest size of 10 million square miles on September 21, 2023, according to an analysis of satellite and balloon-based observations conducted by the United States National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA).

Key Points of Study

• The size of the Antarctic ozone hole varies annually, with it opening in August and closing in November or December.

oIn 2022, when the average size of the ozone hole over Antarctica was 8.91 million square miles and in 2021, it was 8.99 million square miles.

• According to experts, the ozone hole forms due to the Earth's rotation, which generates unique winds over the isolated landmass of Antarctica.
• These winds establish a microclimate, acting as a shield over Antarctica, preventing it from mixing with the surrounding air.
• Antarctic Ozone Hole: It is defined as the total area where ozone amounts are below the historical threshold of 220 Dobson units.
• Ozone Hole: An ozone hole is a region of the stratosphere over Antarctica where the ozone layer is exceptionally depleted.

oThe ozone hole is not technically a “hole” where no ozone is present.

Ozone Layer

• The ozone layer is located in the stratosphere, and it serves as a protective gas shield by absorbing harmful ultraviolet (UV) radiation.
• This shield helps protect us from the negative consequences of excessive UV exposure.
• UV radiation has a significant impact on skin cancer rates, emphasizing the crucial role of preserving the ozone layer.