What is UV and where does it come from?
Although very distant from our planet (~ 150 million km on average), the Sun provides us with light energy and heat, both necessary to sustain life on Earth.
This energy arrives in the form of electromagnetic radiation, which is wave-like in nature and therefore is characterized by a wavelength related to the composition and temperature of the transmitter, in this case, the Sun.
Why should we control the UV doses received and what are the major issues?
Prolonged exposure to ultraviolet radiation can cause significant damage to living organisms.
For example, the painful experience of a sunburn (erythema) is a visible manifestation of a type of defense mechanism set up by the cells of our skin against excessive UV doses.
Installing a monitoring network of UV ground stations
In early 1980, following the discovery of the "ozone hole (.pdf)" above Antarctica (see folder “Aeronomy and ozone”) scientists began to worry about the risks threatening populations, due to a potential increase of UV rays in surface.
To verify the potential for increased UV-B on the ground, better understand the mechanisms of penetration through the atmosphere and to finally establish a climatology, both reliable and continuous, the group "Solar Radiation" of the Belgian Institute for Space Aeronomy (BIRA-IASB) decided to establish a network of measuring ground stations allowing quasi real time tracking (monitoring) of UV-A, UV-B and visible range.
UV measurements from space with solspec instrument aboard the ISS
Since February 2008, the solar radiation (UV-Vis) is also studied from space using the instrument SOLSPEC, a Belgo-Franco-German collaboration that became a standard in measuring the solar spectrum.
SOLSPEC is attached on Columbus module on the International Space Station (ISS) (Photo gallery). It aims to determine the spectral distribution of solar energy and its variation during a solar cycle of eleven years on average.
This should enable one to better identify the close relationship between the variations in Sun energy and the atmosphere and to better quantify their respective changes.