- What are electromagnetic fields?
- Static and low-frequency fields
- What are static and low-frequency electric and magnetic fields?
- Direct and alternating voltage
- Effects of static and low-frequency fields
- Reports & Evaluations
- Radiation protection relating to the expansion of the national grid
- Basics transfer of electrical power
- High-frequency fields
- What are high-frequency fields?
- Applications high-frequency fields
- Radiation protection in mobile communication
- What is mobile communication?
- Reports and evaluations
- What is optical radiation?
- UV radiation
- What is UV radiation?
- Sun but safe!
- What is solar radiation?
- UV radiation and ozone
- Effects of UV radiation
- Protection against UV radiation
- UV index
- Infrared radiation
- What is ionising radiation?
- Radioactivity in the environment
- Where does radioactivity occur in the environment?
- What is the level of natural radiation exposure in Germany?
- Air, soil and water
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UV radiation and ozone
Depending on its wave length, solar radiation varies in terms of intensity and spectral distribution due to absorption while entering the earth’s atmosphere. In addition, the intensity of solar radiation reaching the earth’s surface, i.e. the "subaerial solar radiation", strongly depends on climatic conditions and solar altitude.
Solar UV radiation
The solar UV radiation is absorbed by ozone in the stratosphere and troposphere. This filter function heavily depends on the UV wavelength. UV radiation intensity at ground level decreases markedly with wavelengths below about 330 nanometres (nm). This phenomenon is also referred to as "UV-B border".
UV radiation with wavelengths below about 290 nm (UV-C) is not measurable any more in our latitudes even in summer. According to this, any change in the atmospheric ozone concentration will cause an alteration of the subaerial UV exposure.
Variations of ozone content
The total atmospheric ozone content in our latitudes is subject to natural season variations with a maximum in spring and a minimum in autumn. During the last few years, however, extremely low levels have been recorded particularly in late winter/spring, also referred to as "mini holes in the ozone layer". This is primarily due to the inflow of ozone-depleted air from subtropical latitudes. In addition, the dispersal of the polar vertex in spring might cause a transfer of polar air with low ozone content to moderate latitudes.
Ozone concentration and UV radiation
As a result of decreasing ozone concentrations in the atmosphere there is an increase especially in the intensity of UV-B radiation, i.e. additional very high energy UV radiation is reaching the ground. The biological effectiveness of this radiation component is very high, and even small variations of the ozone content in the stratosphere, therefore, substantially influence the danger potential of sunlight at the earth’s surface.
State of 2017.03.01