Introduction to Ozone and UV

Stratospheric Ozone

Stratospheric ozone is a naturally-occurring gas that filters the sun\'s ultraviolet (UV) radiation. A diminished ozone layer allows more radiation to reach the Earth's surface. Total ozone levels are at their annual peak in the late winter and early spring. However it is also at this time when man-made substances can lead to enhanced ozone depletion in the stratosphere.

It is difficult to quantify these losses over the UK precisely since levels vary naturally by large amounts. The hole in the ozone layer has been a cause for concern for a number of years.

UK ozone levels are recorded regularly to assess the changing state of the ozone layer and help us to understand the effects of different ozone levels on the ground.

You can find out more detailed useful information about Ozone by visiting the following pages:

• How Chlorofluorocarbons (CFCs) get to the Stratosphere when they are heavier than air
• Evidence that stratospheric ozone is destroyed by chlorine and bromine
• Most of the Chlorine in the Stratosphere comes from human sources
• Natural changes such as the sun's output and volcanic eruptions could be responsible for the changes in ozone
• The first appearance of the Antarctic Ozone Hole
• Appearance of an Ozone Hole over Antarctica explained
• Ozone hole over the Arctic
• Depletion of the Ozone Layer leading to an increase in ground-level ultraviolet radiation
• Ozone Depletion and Climate Change
• The Severity of Ozone Depletion
• Ozone layer recovery

UV Radiation

Within these pages we report on the spectral UV measurements made at Reading in the UK. For public information we report the daily UV index in both tabular and graphical form.

The PHE also operates a network of nine broadband UV instruments which provide UV index graphs on a daily basis.

Daily UV forecasts for the UK are also available from the Met Office.