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1. How the ozone hole works
Seasonal cycle
Polar stratospheric clouds (PSCs) form in the long, dark Antarctic winter. When sunlight returns in August–September, chlorine and bromine released from human-made chemicals destroy ozone, creating the “hole.” By November sunlight and winds dilute the depleted air and the hole closes.
Because of that cycle, the map for May (late autumn in Antarctica) normally shows little or no hole, exactly what NASA’s Ozone Watch images display this week.
Trend since the Montreal Protocol
Global bans on CFCs under the 1987 Montreal Protocol have cut surface chlorine by roughly half its 1993 peak, and scientific assessments project Antarctic ozone to return to 1980 levels around 2065-2066.
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2. What happened in 2023 & 2024—and why you heard “largest ever”
Season1-day maximum areaRank (since 1979)Key influences
202310 million mi² (26 million km²) on 21 Sep12th-largestVery cold stratosphere plus extra water vapor from the Hunga Tonga eruption enhanced PSCs.
20248.5 million mi² (22.4 million km²) on 28 Sep7th-smallest since recovery began; 20th-smallest in full 45-yr recordWarmer vortex and continued decline in CFCs; some lingering volcanic influence.
Early-season press or social-media posts sometimes compare instantaneous daily values (which can spike) or focus on different metrics (e.g., depth vs. area), leading to claims that a hole is the “largest ever” even when the seasonal average ranks middle-of-the-pack. NASA and NOAA base their official ranking on the 5-week average from 7 Sep – 13 Oct.
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3. Current status (May 2025)
Total column ozone over the pole is now mostly >300 Dobson Units, well above the 220-DU “hole” threshold.
The ozone-hole area = 0 mi² for most days since late December 2024, which is normal for the austral summer-autumn period.
In the Northern Hemisphere, the Copernicus Atmosphere Monitoring Service (CAMS) reports an unusually low—but not hole-like—ozone pocket over the Arctic in early 2025, driven by a strong polar vortex.
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4. Where to get live maps & data
SourceWhat you’ll seeLink path
NASA Ozone WatchDaily true-color and false-color ozone maps, archive back to
1979ozonewatch.gsfc.nasa.gov → Ozone Maps
CAMS global chartsNear-real-time model-analysis of total ozone & 10-day
forecastatmosphere.copernicu… → Monitoring Ozone
NOAA South-Pole sondesBalloon profiles released weekly through the
wintergml.noaa.gov/obop → ozonesondes
These sites update automatically, so you can save the URLs and check the hole as it develops from late August onward each year.
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5. Take-aways
1. The hole is not growing right now—May is the off-season.
2. 2024’s hole was smaller than average for the 21-st century, reversing the larger 2023 event.
3. Decades-long healing continues, though year-to-year swings will persist until chlorine levels fall further.
4. High-resolution satellite imagery (see carousel above) remains the best way to visualize the hole’s size; you can download daily PNGs directly from NASA Ozone Watch for sharing or printing.