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  2. Solar irradiance - Wikipedia

    en.wikipedia.org/wiki/Solar_irradiance

    Total solar irradiance (TSI) is a measure of the solar power over all wavelengths per unit area incident on the Earth's upper atmosphere. It is measured perpendicular to the incoming sunlight. [3] The solar constant is a conventional measure of mean TSI at a distance of one astronomical unit (AU).

  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. 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 ...

  5. Solar cycle - Wikipedia

    en.wikipedia.org/wiki/Solar_cycle

    The Suess cycle, or de Vries cycle, is a cycle present in radiocarbon proxies of solar activity with a period of about 210 years. It was named after Hans Eduard Suess and Hessel de Vries . [ 48 ] Despite calculated radioisotope production rates being well correlated with the 400-year sunspot record, there is little evidence of the Suess cycle ...

  6. Water cycle - Wikipedia

    en.wikipedia.org/wiki/Water_cycle

    The water cycle (or hydrologic cycle or hydrological cycle), is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time. However, the partitioning of the water into the major reservoirs of ice, fresh water, salt water and ...

  7. Solar energy - Wikipedia

    en.wikipedia.org/wiki/Solar_energy

    The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. [7] Most of the world's population live in areas with insolation levels of 150–300 watts/m 2 , or 3.5–7.0 kWh /m 2 per day.

  8. Diurnal cycle - Wikipedia

    en.wikipedia.org/wiki/Diurnal_cycle

    A diurnal cycle (or diel cycle) is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis. [1] Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as weather changes throughout the year. The diurnal cycle depends mainly on incoming solar radiation.

  9. Photosynthetically active radiation - Wikipedia

    en.wikipedia.org/wiki/Photosynthetically_active...

    Photosynthetically active radiation (PAR) designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to the human eye. Photons at shorter wavelengths tend to ...