Daily Current Affairs : 27-November-2023
The ozone layer, located in the upper atmosphere, plays a crucial role in shielding Earth from harmful solar radiation. It spans approximately 15 to 35 km above the Earth’s surface and is rich in ozone molecules, particularly in the stratosphere.
Defining Ozone Holes
Contrary to its name, the ‘ozone hole’ is not an actual gap but refers to a region where ozone concentrations plummet during specific months. The most renowned ‘ozone holes’ emerge over Antarctica, occurring from September to November. North Pole also witnesses such holes, albeit smaller due to milder temperatures.
Ozone Creation and Destruction
Ozone production in the stratosphere stems from the breaking of chemical bonds within oxygen molecules, triggered by high-energy solar photons. This process, called photodissociation, results in the formation of ozone. However, human activities, particularly the release of chlorine and bromine from chlorofluorocarbons (CFCs), have significantly altered the ozone layer, leading to its depletion.
Ozone Holes: Annual Fluctuations
The size of the Antarctic ozone hole fluctuates annually, usually opening in August and closing by November or December. This cyclical pattern is influenced by special winds over Antarctica, forming a protective shield over the continent.
Causes of the Giant Ozone Hole in 2023
The unprecedented size of the ozone hole in 2023 may be attributed to volcanic eruptions at Hunga Tonga in Tonga. These eruptions released water vapor into the stratosphere, impacting the ozone layer through chemical reactions and introducing elements like bromine and iodine, known to deplete ozone.
Climate Change and Ozone Holes
While ozone depletion is not a primary driver of climate change, rising temperatures could influence ozone holes. Mitigation efforts have been successful since the 1980s, but recent anomalies, such as the deep and long-lasting 2020 and 2021 ozone holes, raise questions. Wildfires in southeastern Australia in 2020 contributed to the ozone hole, highlighting potential interactions between climate change and ozone depletion.
Important Points:
- Ozone Layer Basics:
- Located 15 to 35 km above Earth’s surface.
- Contains high concentrations of ozone molecules.
- Blocks solar radiation, protecting from harmful UV and other radiation.
- Ozone Holes:
- Not actual holes but regions with extremely low ozone concentrations.
- Most discussed over Antarctica, occurring from September to November.
- Also found over the North Pole but smaller due to warmer temperatures.
- Ozone Creation and Destruction:
- Ozone production in stratosphere through photodissociation.
- Human activities, particularly CFCs, have substantially altered the ozone layer.
- Ozone depletion most pronounced in polar regions, linked to increase in chlorine and bromine.
- Annual Fluctuations in Ozone Holes:
- Size of Antarctic ozone hole changes annually.
- Typically opens in August and closes by November or December.
- Influenced by special winds over Antarctica creating a protective shield.
- Causes of the 2023 Ozone Hole:
- Potentially linked to volcanic eruptions at Hunga Tonga in Tonga.
- Eruptions released water vapor into the stratosphere.
- Impact on ozone layer through chemical reactions, introducing elements like bromine and iodine.
- Climate Change and Ozone Holes:
- Ozone depletion not a primary driver of climate change.
- Rising temperatures could influence ozone holes.
- Mitigation efforts effective since the 1980s, but recent anomalies raise questions.
Why In News
According to a recent study published in Nature Communications, it has been reported that the Antarctic Ozone Hole has been massive in the last four years, raising concerns about its potential impact on global climate patterns and emphasizing the urgent need for international cooperation in addressing environmental challenges.
MCQs about Decoding Ozone Layers and Unraveling Mysteries
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What is the primary role of the ozone layer in the atmosphere?
A. To trap greenhouse gases
B. To block harmful solar radiation
C. To regulate air temperature
D. To promote cloud formation
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When do the most discussed ‘ozone holes’ over Antarctica typically occur?
A. January to March
B. April to June
C. September to November
D. December to February
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What is the main cause of ozone depletion in the stratosphere?
A. Natural climate variability
B. Release of carbon dioxide
C. Increase in chlorine and bromine
D. Ozone layer aging
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What potentially contributed to the unusually large ozone hole in 2023?
A. Wildfires in Australia
B. Industrial pollution
C. Volcanic eruptions in Tonga
D. CFC emissions
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