The study looked at how the movement and chemical reactions in the Earth's upper atmosphere affect ozone levels in the northern hemisphere. They used a computer model to simulate different scenarios, like warm and cold winters, to see how ozone is affected. They found that ozone loss mainly happens inside a swirling air mass called the polar vortex, but can also occur outside of it due to certain events. When the polar vortex changes shape or moves, it can lead to significant ozone depletion. However, a small warming in the atmosphere can stop chlorine compounds from harming the ozone layer. In areas away from the poles, changes in ozone levels can be intensified by certain chemical reactions.