Radiation with wavelengths roughly between 200 and 400 nanometers.
These wavelengths are shorter than those which characterize visible
light. Observations from satellites in the UV and extreme UV (EUV)
wavelengths have demonstrated the sun's UV variability over short time
scales of days and weeks. UV variability is linked to solar magnetic
activity phenomena such as flares and plages. Studies of the UV and EUV
irradiance variability may have indicated influences on the Earth's
climate dynamics.
