Is Ozone hole over only Antarctica?

While the Antarctic ozone hole is the most well-known and largest ozone hole, ozone depletion occurs globally beyond the tropics with severe seasonal depletion in the polar regions in both hemispheres.

What is the Antarctic Ozone Hole?

• The Antarctic ozone hole refers to severe thinning of ozone levels in the stratosphere over Antarctica during spring, with ozone levels dropping by over 50% since 1975.
• It forms every year from September to early December aided by circumpolar winds that isolate Antarctic air. Complex chemical processes involving chlorofluorocarbons then destroy ozone.

Arctic Ozone Depletion Also Occurs

• Recent data shows similar ozone destruction patterns in the Arctic stratosphere during springtime, though not as severe as Antarctica due to higher temperatures.
• In some years, the Arctic ozone hole has reached sizes nearly twice that of Antarctica. This can allow increased UV exposure for Northern Hemisphere populations.

Global Impact and Repair of Ozone Holes

• The polar ozone holes repair themselves by December-January as temperatures rise and atmospheric mixing occurs. But the cycle repeats annually.
• Since the 1970s, the Antarctic hole has both widened and deepened, indicating more severe ozone destruction over time.
• Breakdown of the Antarctic ozone hole causes ozone-depleted air to drift to nearby regions like New Zealand, causing up to 10% ozone decreases.
• Conditions that promote ozone depletion exist globally. Cooling stratospheric temperatures could accelerate worldwide ozone destruction.

Key Takeaways

• Ozone depletion and polar ozone holes are global phenomena not restricted solely to Antarctica.
• The developing Arctic ozone hole in particular warrants concern for potential UV exposure effects on Northern Hemisphere populations.
• Global coordination is required to address worsening worldwide ozone destruction patterns through reduction of ozone-depleting substances.