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solar activity

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airglow

airglow  

A weak background emission of light over the whole sky, resulting mainly from the excitation of atmospheric oxygen at an altitude of around 100 km by solar radiation; also known as nightglow. Airglow ...
Alexander von Humboldt

Alexander von Humboldt  

(b. Berlin, 14 September 1769; d. Berlin, 6 May 1859)German naturalist and explorer who made major contributions to various sciences, including geology, geomagnetism, and meteorology. Together with ...
alternative energy

alternative energy  

Energy that is produced from sources other than fossil fuels, which includes sources such as compressed natural gas, solar, hydroelectric, or wind energy.
Edward Appleton

Edward Appleton  

Reference type:
Overview Page
(1892–1965)British physicist, who discovered and investigated the properties of the ionosphere. He was knighted in 1941 and awarded the Nobel Prize for Physics in 1947.Born in Bradford, he studied ...
energy source

energy source  

Any material that is used to produce energy, including fossil fuels (coal, oil, gas), nuclear (fission and fusion), and renewables (solar, wind, geothermal, biomass, hydroelectric).
exosphere

exosphere  

Outer region of the upper atmosphere extending from a base of 500–750 km altitude. The zone has a very low concentration of gases (mostly molecules of oxygen, hydrogen, and helium, although some are ...
planetary albedo

planetary albedo  

The fraction (approximately 30%) of incident solar radiation that is reflected by the Earth–atmosphere system and returned to space, mostly by backscatter from clouds in the atmosphere. See also ...
solar activity and sunspots

solar activity and sunspots   Reference library

The Oxford Companion to the Earth

Reference type:
Subject Reference
Current Version:
2003

The Sun provides most of the extraterrestrial energy which reaches the Earth's surface. The average annual energy reaching the Earth

solar architecture

solar architecture  

The design and building of structures that are energy efficient in terms of solar energy, involving a combination of technologies including solar panels and photovoltaic systems.
solar constant

solar constant  

The rate per unit area at which solar radiation reaches the outer margin of the earth's atmosphere. This fixes the energy supply for the atmospheric heat engine. Gribben (1991) New Scientist 132, ...
solar cycle

solar cycle  

A variation of activity on the Sun over an 11-year period indicated primarily by the number of sunspots visible on its surface. The next period of maximum activity is expected round 2011.
solar luminosity

solar luminosity  

A measure of the brightness of the Sun, which is determined by the amount of solar radiation it is emitting.
solar thermal electric technology

solar thermal electric technology  

A range of technologies that are similar in concept to solar heating technologies in using sunlight to generate heat, but they create enough heat to power a generator, which is then used to produce ...
solar–terrestrial relations

solar–terrestrial relations  

The effects of solar activity on the Earth and its magnetic field. The largest effects originate from magnetic disturbances which travel out from the Sun and produce geomagnetic storms as they ...
solar activity

solar activity   Quick reference

A Dictionary of Weather (2 ed.)

Reference type:
Subject Reference
Current Version:
2008

The general term for all forms of active phenomena on the Sun, including solar flares and sunspots. All solar

Spörer Minimum

Spörer Minimum  

A period between about ad 1450 and 1550 when activity on the Sun seems to have been unusually low, as judged from historical records of naked-eye sightings of sunspots and aurorae, and from ...
sun

sun  

Reference type:
Overview Page
The central star (G spectral type) in the solar system, 696 000 km in radius, 333 000 × Earth mass, 1 300 000 × Earth volume, and with a mean density of 1410 kg/m3. The equator is inclined at 7.25° ...
sunspot

sunspot  

A relatively dark area on the Sun's surface. The centre of a sunspot is at a temperature of c.4 500 K, and therefore appears darker than the surrounding photosphere, which has a temperature of ...
thermopause

thermopause  

The transitional layer between the thermosphere and the overlying exosphere. The transition is poorly defined, but may be taken to lie at between c.200 and c.700 km, depending on solar activity.
tidal range

tidal range  

The difference in height between consecutive high and low waters. The tidal range varies from a maximum during spring tides to a minimum during neap tides. In tide tables daily high- and low-water ...

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