Ozone Layer & UV Radiation Lab
Run a simplified Chapman cycle: balance ozone production against natural and CFC-driven catalytic destruction, and watch surface UV respond.
How to use: raise UV intensity and CFC (chlorine source) level and watch the simplified Chapman cycle balance ozone production against natural and catalytic destruction, then see how surface UV index responds to the shrinking ozone column.
Challenge 1: open an ozone hole
Raise CFC level high enough and run time forward until the ozone column drops below 220 Dobson Units (the real "ozone hole" threshold).
Challenge 2: recover the layer (Montreal Protocol)
Starting from a depleted layer, cut CFC level to near zero and run time forward until the column recovers above 300 Dobson Units.
About the Ozone Layer & UV Radiation Lab
Free ozone layer & uv radiation lab. Run a simplified Chapman cycle: balance ozone production against natural and CFC-driven catalytic destruction, and watch surface UV respond. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for environmental science, the ozone layer & uv radiation lab runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Run a simplified Chapman cycle: balance ozone production against natural and CFC-driven catalytic destruction, and watch surface UV respond. Use it to explore environmental science ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Ozone Layer & UV Radiation Lab
- Use the controls to change UV intensity (relative), O₂ concentration (relative), CFC / chlorine level (ppb-equivalent). The simulation reacts instantly.
- Press "▶ Run years", "Reset layer", "📉 Jump to 1990s-style peak CFC", "Reset to defaults" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Push CFC level high and run time forward until an ozone hole (below 220 DU) opens.
- From a depleted state, cut CFC to near zero and run time forward to watch recovery.
- Raise UV intensity alone (no CFC) and see production and natural destruction both rise together.
- Compare surface UV index at 300 DU versus 150 DU.
Key ideas you can learn
- Ozone is continuously created when UV light splits O₂ into single oxygen atoms that combine with more O₂ to form O₃ - part of the Chapman cycle.
- Ozone is also naturally destroyed when UV light splits it back into O₂ and O, which is itself part of what makes the ozone layer such an effective UV shield.
- CFCs release chlorine atoms high in the stratosphere that catalytically destroy ozone - each chlorine atom can break down tens of thousands of ozone molecules without being consumed, so small CFC amounts cause outsized damage.
- Less stratospheric ozone lets more UV radiation reach the surface, since the ozone column's UV absorption falls off roughly exponentially with its thickness (measured in Dobson Units, DU).
Where this is used in the real world
Atmospheric scientists used exactly this kind of Chapman-cycle and chlorine-catalysis modeling to predict and later confirm the Antarctic ozone hole, leading to the 1987 Montreal Protocol banning CFCs.
Who is this simulation for?
Students, teachers and curious learners of all ages.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why can a small amount of CFCs destroy so much ozone?
Chlorine released from CFCs acts as a catalyst: it destroys an ozone molecule but is regenerated in the process (Cl + O3 → ClO + O2, then ClO reactions release Cl again), letting a single chlorine atom destroy tens of thousands of ozone molecules before it is finally removed from the stratosphere.
Why did the ozone layer only start recovering after the Montreal Protocol banned CFCs, rather than immediately?
CFCs are extremely long-lived and take decades to break down and clear from the stratosphere even after emissions stop, so the chlorine they already released kept destroying ozone for years, and the ozone column only slowly climbed back once new chlorine input was cut off.
Is the Ozone Layer & UV Radiation Lab free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Ozone Layer & UV Radiation Lab work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.