Recently NIWA installed a UV monitor at Rarotonga so that UV in New Zealand can be directly compared with that at sea level in the tropics. The model calculation in Figure 1, which does not include these processes, shows a recovery beginning before the end of the century. Incomplete future compliance to the Montreal Protocol, or future volcanic eruptions, would also delay ozone recovery. Full recovery is unlikely to occur until the middle of the 21st Century at the earliest. The solid lines show the changes in summertime ozone that have occurred since the 1970s and the deduced changes in clear-sky UV expected from these changes in ozone.
Higher values correspond to higher intensities.