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  2. List of weather records - Wikipedia

    en.wikipedia.org/wiki/List_of_weather_records

    The highest natural ground surface temperature ever recorded may have been an alleged reading of 93.9 °C (201.0 °F) at Furnace Creek, California, United States, on 15 July 1972. [7] In 2011, a ground temperature of 84 °C (183.2 °F) was recorded in Port Sudan, Sudan. [8] The theoretical maximum possible ground surface temperature has been ...

  3. Ultraviolet index - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_index

    The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn -producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public. The UV index is designed as an open-ended linear scale, directly proportional to the ...

  4. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    The amount of penetration of UV relative to altitude in Earth's ozone. Next in frequency comes ultraviolet (UV). In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC.

  5. Ultraviolet - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet

    Ultraviolet (UV) light is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and ...

  6. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    The term ultraviolet refers to the fact that the radiation is at higher frequency than violet light (and, hence, also invisible to the human eye). Due to absorption by the atmosphere very little reaches Earth's surface. This spectrum of radiation has germicidal properties, as used in germicidal lamps. Ultraviolet B or (UVB) range spans 280 to ...

  7. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    The mesosphere is the third highest layer of Earth's atmosphere, occupying the region above the stratosphere and below the thermosphere. It extends from the stratopause at an altitude of about 50 km (31 mi; 160,000 ft) to the mesopause at 80–85 km (50–53 mi; 260,000–280,000 ft) above sea level.

  8. Van Allen radiation belt - Wikipedia

    en.wikipedia.org/wiki/Van_Allen_radiation_belt

    The inner Van Allen Belt extends typically from an altitude of 0.2 to 2 Earth radii (L values of 1.2 to 3) or 1,000 km (620 mi) to 12,000 km (7,500 mi) above the Earth. [ 4 ] [ 16 ] In certain cases, when solar activity is stronger or in geographical areas such as the South Atlantic Anomaly , the inner boundary may decline to roughly 200 km ...

  9. Health effects of sunlight exposure - Wikipedia

    en.wikipedia.org/wiki/Health_effects_of_sunlight...

    Exposure of skin to ultraviolet radiation from sunlight presents both positive and negative health effects. On the positive side, UV exposure enables the synthesis of vitamin D3, which is essential for bone health [1] and potentially plays a role in inhibiting certain cancers. [2][3] While vitamin D can also be obtained through dietary ...