“aurora”的概念、定义、翻译、参考文献-科学参考

aurora

Physics

The luminous phenomena seen in the night sky in high latitudes, occurring most frequently near the earth’s geomagnetic poles. The displays of aurora appear as coloured arcs, rays, bands, streamers, and curtains, usually green or red. The aurora is caused by the interaction of the atoms (mainly atomic oxygen) and molecules in the upper atmosphere (above about 100 km) with charged particles streaming from the sun, attracted to the auroral regions by the earth’s magnetic field. The aurora is known as the aurora borealis (or northern lights) in the northern hemisphere and as the aurora australis (or southern lights) in the southern hemisphere.

Astronomy

An emission of light from the Earth’s high atmosphere, caused principally by oxygen atoms and nitrogen molecules that are excited by collisions with electrons accelerated within the magnetosphere. The visible aurora is dominated by the green (557.7 nm wavelength) and red (630 nm) emissions of oxygen, occurring respectively at altitudes of 100 km and above about 400 km, and red (661–686 nm) nitrogen emissions at about 95 km. Violet purple (391.4 nm) nitrogen emissions are sometimes seen in the sunlit uppermost parts of aurorae at altitudes of 1000 km.
Popularly known as the northern lights (or southern lights in the southern hemisphere), the aurora takes a number of characteristic forms. These may range from a glow, low over the northern horizon (from which the aurora borealis—‘northern dawn’—takes its name), through arcs and bands, which may be homogeneous, or may show vertical rays. Isolated rays and patches of auroral light may also be seen. Most spectacular of all is the corona, a perspective effect whereby rays appear to converge on a single region of the sky almost overhead during a particularly intense storm. During strong activity, the rays and other structures move, causing a ‘curtain’ effect, and there may often be rapid changes in brightness. The aurora is seen from the southern hemisphere as the aurora australis, a mirror-image of activity present at the same time over the opposite hemisphere of the Earth.
Auroral activity is present more or less continuously in a ring around the north and south magnetic poles called the auroral ovals. Observers at lower latitudes, such as in the British Isles, southern United States, or Australasia, see auroral activity only when the magnetosphere is disturbed by fast-moving streams of solar wind from coronal holes and coronal mass ejections. At such times the Kp index rises to high values. Aurorae also occur on Jupiter, Saturn, Uranus, and Neptune.
http://earthobservatory.nasa.gov/IOTD/view.php?id=44348&src=fb

Space Exploration

The coloured light in the night sky near the Earth's magnetic poles, called aurora borealis (‘northern lights’) in the northern hemisphere and aurora australis (‘southern lights’) in the southern hemisphere. Although aurorae are usually restricted to the polar skies, fluctuations in the solar wind occasionally cause them to be visible at lower latitudes. An aurora is usually in the form of a luminous arch with its apex towards the magnetic pole, followed by arcs, bands, rays, curtains, and coronae, usually green but often showing shades of blue and red, and sometimes yellow or white. Aurorae are caused at heights of over 100 km by a fast stream of charged particles from solar flares and low-density ‘holes’ in the Sun's corona. These are guided by the Earth's magnetic field towards the north and south magnetic poles, where they enter the upper atmosphere and bombard the gases in the atmosphere, causing them to emit visible light.
http://www.exploratorium.edu/learning_studio/auroras/ Take a tour of the aurorae. This page provides an in-depth explanation for the aurora phenomenon, includes a number of images taken from Earth and space, and sheds light on where they are best viewed. You can view a video clip of the aurora borealis and listen to audio clips of David Stern of NASA.

Geology and Earth Sciences

Illumination of the sky, sometimes in brilliant colours, as a result of high-speed solar particles entering the ionosphere (at a height of 100–130 km) and releasing electrons from air molecules by excitation. The re-establishment of molecules leads to the emission of light, especially red- and green-coloured light, e.g. in arcs or bands over large areas. The effect is called ‘aurora borealis’ or ‘northern lights’ in the northern hemisphere and ‘aurora australis’ or ‘southern lights’ in the southern hemisphere. Such atmospheric disturbances occur in relation to disturbances on the Sun in the course of the sunspot cycle.

单词	aurora
释义	aurora Physics The luminous phenomena seen in the night sky in high latitudes, occurring most frequently near the earth’s geomagnetic poles. The displays of aurora appear as coloured arcs, rays, bands, streamers, and curtains, usually green or red. The aurora is caused by the interaction of the atoms (mainly atomic oxygen) and molecules in the upper atmosphere (above about 100 km) with charged particles streaming from the sun, attracted to the auroral regions by the earth’s magnetic field. The aurora is known as the aurora borealis (or northern lights) in the northern hemisphere and as the aurora australis (or southern lights) in the southern hemisphere. Astronomy An emission of light from the Earth’s high atmosphere, caused principally by oxygen atoms and nitrogen molecules that are excited by collisions with electrons accelerated within the magnetosphere. The visible aurora is dominated by the green (557.7 nm wavelength) and red (630 nm) emissions of oxygen, occurring respectively at altitudes of 100 km and above about 400 km, and red (661–686 nm) nitrogen emissions at about 95 km. Violet purple (391.4 nm) nitrogen emissions are sometimes seen in the sunlit uppermost parts of aurorae at altitudes of 1000 km. Popularly known as the northern lights (or southern lights in the southern hemisphere), the aurora takes a number of characteristic forms. These may range from a glow, low over the northern horizon (from which the aurora borealis—‘northern dawn’—takes its name), through arcs and bands, which may be homogeneous, or may show vertical rays. Isolated rays and patches of auroral light may also be seen. Most spectacular of all is the corona, a perspective effect whereby rays appear to converge on a single region of the sky almost overhead during a particularly intense storm. During strong activity, the rays and other structures move, causing a ‘curtain’ effect, and there may often be rapid changes in brightness. The aurora is seen from the southern hemisphere as the aurora australis, a mirror-image of activity present at the same time over the opposite hemisphere of the Earth. Auroral activity is present more or less continuously in a ring around the north and south magnetic poles called the auroral ovals. Observers at lower latitudes, such as in the British Isles, southern United States, or Australasia, see auroral activity only when the magnetosphere is disturbed by fast-moving streams of solar wind from coronal holes and coronal mass ejections. At such times the Kp index rises to high values. Aurorae also occur on Jupiter, Saturn, Uranus, and Neptune. http://earthobservatory.nasa.gov/IOTD/view.php?id=44348&src=fb Space Exploration The coloured light in the night sky near the Earth's magnetic poles, called aurora borealis (‘northern lights’) in the northern hemisphere and aurora australis (‘southern lights’) in the southern hemisphere. Although aurorae are usually restricted to the polar skies, fluctuations in the solar wind occasionally cause them to be visible at lower latitudes. An aurora is usually in the form of a luminous arch with its apex towards the magnetic pole, followed by arcs, bands, rays, curtains, and coronae, usually green but often showing shades of blue and red, and sometimes yellow or white. Aurorae are caused at heights of over 100 km by a fast stream of charged particles from solar flares and low-density ‘holes’ in the Sun's corona. These are guided by the Earth's magnetic field towards the north and south magnetic poles, where they enter the upper atmosphere and bombard the gases in the atmosphere, causing them to emit visible light. http://www.exploratorium.edu/learning_studio/auroras/ Take a tour of the aurorae. This page provides an in-depth explanation for the aurora phenomenon, includes a number of images taken from Earth and space, and sheds light on where they are best viewed. You can view a video clip of the aurora borealis and listen to audio clips of David Stern of NASA. Geology and Earth Sciences Illumination of the sky, sometimes in brilliant colours, as a result of high-speed solar particles entering the ionosphere (at a height of 100–130 km) and releasing electrons from air molecules by excitation. The re-establishment of molecules leads to the emission of light, especially red- and green-coloured light, e.g. in arcs or bands over large areas. The effect is called ‘aurora borealis’ or ‘northern lights’ in the northern hemisphere and ‘aurora australis’ or ‘southern lights’ in the southern hemisphere. Such atmospheric disturbances occur in relation to disturbances on the Sun in the course of the sunspot cycle.
随便看	steady flow steady state steady-state approximation steady state landscape steady-state theory stealth technology stealth virus steam steam cracking steam cycle steam distillation steam engine steam fog steam injection steam jacket steam jet ejector steam point steam power steam reforming steam tables steam tracing steam trap steam turbine stearate stearic acid