Diurnal Circle
Related Category: Astronomy: General
(dûr´nl), apparent path followed by a star due to the earth's rotation on its axis.
Diurnal motion
Diurnal motion is an astronomical term referring to the apparent daily motion of stars around the Earth, or more precisely around the two celestial poles.
Diurnal motion The daily motion of the sky produced by rotation of the Earth, causing the rising and setting of the Sun, Moon, planets and stars.
Diurnal may refer to:* Diurnality, the behavior of an animal that is active in the daytime* Diurnal motion, the apparent motion of stars around the Earth...
(time of day) effect and a seasonal effect. The local winter hemisphere
Earth ...
Diurnal: A single daily cycle.
Earthquake: Sudden motion or trembling of Earth caused by the abrupt release of slowly accumulated elastic energy in rocks.
Diurnal - Daily
Diurnal Circle - The circular path that a celestial body traces out as it appears to move across the sky during an entire day. Diurnal circles are centered on the north and south celestial poles ...
Diurnal. Another name for daily.
Doppler effect. The change in frequency (or wavelength) of light (or other radiation) caused by the motion of an object or the observer.
Diurnal Motion
(a) The apparent westward motion of celestial bodies, as seen from Earth, due to the Earth's axial rotation.
(b) The apparent daily motion of celestial bodies across the sky from east to west, caused by the Earth's rotation.
diurnal arches: an old term (probably 17th century) for lines on a dial face showing the length of the day time. They are thus declination lines, but for declinations selected to give particular lengths of the day.
SEMIDIURNAL TIDE
A semidiurnal tide tide is a tide having a period of about 12 hours; it has two high waters and two low waters during a tidal day.
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Diurnal motion at different latitudes
Actually, all objects are slowly changing their relative positions on the celestial sphere, but for most the motion is so slow that it cannot be detected over timespans comparable to a human lifetime; ...
Diurnal motion
The apparent motion of the sky from East to West caused by the Earth moving from West to East.
Earthshine ...
DIURNAL TIDE
A diurnal tide (also called a single day tide) is a tide with only one high water and one low water occurring during a lunar (tidal) day.
DOCKING
Docking is when two join together in space.
Diurnal Variation.-The apparent daily period at most stations is largely determined by the influence of daylight on the visibility.
diurnal (NASA SP-7, 1965) Having a period of, occurring in, or related to a day. diurnal aberration (NASA SP-7, 1965) Aberration caused by the rotation of the earth.
semidiurnal Having a period of, occurring in, or related to approximately half a day. semimajor axis (symbol a ) One-half the longest diameter of an ellipse. semiminor axis (symbol b ) One-half the shortest diameter of an ellipse.
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106. Diurnal Motion
The apparent daily rotation of the sky.
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107. Doppler Broadening
The smearing of spectral lines because of the motion of atoms in the gas.
A disk also refers to the apparent circular shape of the Sun and the Moon, or of a planet when viewed through a telescope.
diurnal motion
The apparent daily motion of the objects of the solar system against the background stars.
3. This daily, or diurnal, motion of the stars is very apparent in a time exposure photograph, because the stars appear as streaks due to their apparent motion, or, if you prefer, due to the rotation of the earth under the objects seen in the sky.
A worldwide disturbance of the earth's magnetic field, distinct from regular diurnal variations. Minor Geomagnetic Storm: A storm for which the Ap index was greater than 29 and less than 50.
The Sun reaches winter solstice around December 21 and you see the least part of its diurnal path all year---this is the day of the least amount of daylight and marks the beginning of the season of winter for the northern hemisphere.
The diurnal variation is greatest near the ground and occurs because the surface is able to quickly radiate its heat during the night. During dust storms, this ability is impaired, and the daily temperature swing is reduced.
This pressure varies, of course, with the diurnal moon cycle. One source of its atmosphere is outgassing-the release of gases such as radon that originate by radioactive decay processes within the crust and mantle.
As the Earth turns, there are generally two high tides and two low tides (semi-diurnal tides) in this 24 hour and 50 minute period.
A boundary-layer volatiles diurnal behavior and location also helps to distinguish it from clouds and limb haze.
(b) A measure of time that conforms, within a close approximation, to the mean diurnal motion of the Sun and serves as the basis of all civil timekeeping. UT is formally defined by a mathematical formula as a function of sidereal time.
-- Diurnal, ∨ Geocentric, parallax, the parallax of a body with reference to the earth's center. This is the kind of parallax that is generally understood when the term is used without qualification.
The daily progress of the Sun and the other stars across the sky is known as diurnal motion. As we have just seen, it is a consequence of Earth's rotation.
Astronomy teaches that as well as its diurnal rotation upon its axis, the Earth also has a precessional motion involving a slow periodic shift of the axis itself; approximately one degree every 70 years.
At many locations, surface turbulence follows a diurnal cycle from a minimum just after sunrise, steeply rising to a peak during early afternoon, declining to a secondary minimum shortly after sunset, ...
UT is determined from observations of the diurnal (daily) motions of the stars for an observer on the earth.
His last telescopic discovery--that of the Moon's diurnal and monthly librations (wobbling from side to side)--was made in 1637, only a few months before he became blind. But the fire of his genius was not even yet extinct.
There are three components of the aberration of starlight: annual aberration (up to 20.47") caused by Earth's revolution around the Sun, diurnal aberration (up to 0.3") caused by Earth's axial rotation, ...
Telescope mounting, equatorial:
One rotatable axis, set parallel to the earth's axis of rotation, compensates for diurnal motion of the heavenly bodies in right ascension. The other axis permits adjustment in declination.
A Dictionary of Astronomy entry for diurnal parallax
The Concise Oxford Dictionary of English Etymology entry for parallax
The Oxford Companion to Ships and the Sea entry for parallax
World Encyclopedia entry for parallax ...
Geomagnetic Storm. A worldwide disturbance of the Earth's magnetic field, distinct from regular diurnal variations.
Geocentric. Centered on the Earth.
The extrapolation method assumes that atmospheric systems will propagate at similar speeds in the near future to those seen in the past. This method achieves the best results when diurnal changes in the pressure and precipitation patterns are taken ...
In contrast, the diurnal temperatures at the northern landing site (Viking Lander 2) during midwinter dust storms varied as little as 4°C (7°F) on some days. The lowest predawn temperature was -120°C (-184°F), about the frost point ofcarbon dioxide.
This is a periodic variation that repeats itself after 960 years. A smaller annual variation also exists, as does a diurnal, or daily, variation, both of which can be detected only by sensitive instruments.
The Sun also moves through the Zodiac, though its apparent motion (diurnal motion) is actually caused by the movement of Earth. It is worth noting here that as a result of precession the constellations have moved over 30º eastwards.
down to the surface allowed reconstruction of profiles of the atmospheric density, temperature, and pressure. On the ground, the meteorology package collected temperature, pressure, and wind data for use in the study and characterization of diurnal ...
 See also: Earth, Time, Sun, Solar, Period
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