iPedia Free Information Center

Information about Sunrise

Enlarge picture
A typical sunrise, in New Zealand
Enlarge picture
A sunrise through clouds over Oakland, California.
Enlarge picture
A GIF video of the rising sun
Enlarge picture
Orbital sunrise from Shuttle Endeavour.


Sunrise is the time at which the first part of the Sun appears above the horizon in the east. Sunrise should not be confused with dawn, which is the (variously defined) point at which the sky begins to lighten, some time before the sun itself appears, ending twilight. Because atmospheric refraction causes the sun to be seen while it is still below the horizon, both sunrise and sunset are, from one point of view, optical illusions. The sun also appears larger on the horizon, but this is another optical illusion, similar to the moon illusion.

The apparent westward revolution of Sun around the earth after rising out of the horizon is due to the Earth's eastward rotation. This illusion is so convincing that most cultures had mythologies and religions built around the geocentric model. This same effect can be seen with near-polar satellites as well.

As sunrise and sunset are calculated from the leading and trailing edges of the Sun, and not the center; this slightly increases the duration of "day" relative to "night." The sunrise equation, however, is based on the center of the sun.

In the Northern Hemisphere, the latest sunrise does not occur on the winter solstice around December 21, but rather in early January. Likewise, the earliest sunrise is not on the summer solstice around June 21, but occurs earlier in June in the Northern Hemisphere. As one travels further from the equator, the times of sunrise and sunset change throughout the year. Even on the equator, sunrise and sunset shift several minutes back and forth through the year, along with solar noon. These effect are plotted using an analemma.

Due to Earth's axial tilt, whenever and wherever sunrise occurs, it is always in the northeast quadrant from the March equinox to the September equinox and in the southeast quadrant from the September equinox to the March equinox.

The colors of the sky, throughout the day and at sunrise and sunset, are explained by the phenomena of both Rayleigh Scattering and Mie Scattering.

Rayleigh Scattering causes the hues of blue, violet, and green in the sky. Rayleigh Scattering is scattering of shorter wavelength light, (e.g. blue & violet), by air atoms and molecules, (not statistical variations in density of the Earth's atmosphere). The magnitude or strength of Rayleigh Scattering varies by the reciprocal of the wavelength raised to the fourth power, and hence, does not explain the beautiful variations of reds, purples, oranges, and peachy colors.

The latter colors arise from Mie Scattering, low angle scattering of light off of dust, soot, smoke, and ash particles. Mie Scattering, (producing the colors of sunset and sunrise), is recognizable down-wind of and after dust storms, forest fires, and volcanic eruptions that inject large quantities of fine particulate matter into the atmosphere. A number of eruptions in recent times, such as those of Mount Pinatubo in 1991 and Krakatoa in 1883, have been sufficiently large to produce remarkable sunsets and sunrises all over the world.

Sometimes just before sunrise or after sunset the atmosphere refracts light, causing a blue or green flash.

Gallery




Sunrise in Virginia Beach, VA, United States

Sunrise over the Mississippi River in Muscatine, Iowa

yellowish hue of the sun rising over Verde Island

Sunrise over a dune in Morocco

Sunrise over Greater Los Angeles

Sunrise in Kona, Hawaii

Glowing clouds in Great Sacandaga Lake

Bucklands Beach, Auckland, New Zealand

Sunrise in Daytona Beach, Florida.


See also

External links

time.

One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.
..... Click the link for more information.
The Sun

Observation data
Mean distance
from Earth 1.4961011 m
(8.31 min at light speed)
Visual brightness (V) −26.74m [1]
Absolute magnitude 4.
..... Click the link for more information.
horizon (Ancient Greek ὁ ὁρίζων, /ho horídzôn/, from ὁρίζειν, "to limit") is the line that separates earth from sky.
..... Click the link for more information.
East is a direction in geography. It is one of the four cardinal directions or compass points, opposite of west and at right angles to north and south. East is the direction toward which the Earth rotates about its axis, and therefore the general direction from which the
..... Click the link for more information.
DAWN as an acronym (all caps) may refer to:
  • Dawn (spacecraft), a space orbiter launched in 2007 to the asteroid Vesta and the dwarf planet Ceres
  • DAWN, an English-language newspaper in Pakistan
  • DC Anti-War Network, a Washington DC-based anti-war organization

..... Click the link for more information.
The sky is the part of the atmosphere or of outer space visible from the surface of any astronomical object. It is difficult to define precisely for several reasons.
..... Click the link for more information.
Twilight is the time before sunrise or after sunset when sunlight scattered in the upper atmosphere illuminates the lower atmosphere and the surface of the Earth is between light and dark.
..... Click the link for more information.
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of altitude.
..... Click the link for more information.
optical illusion is always characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a
..... Click the link for more information.
The Moon illusion is a visual illusion (or optical illusion) in which the Moon appears larger near the horizon than it does while higher up in the sky. This optical illusion also occurs with the Sun and star constellations.
..... Click the link for more information.
WEST can refer to:
  • Western European Summer Time
  • WEST (AM), an AM radio station located in Easton, Pennsylvania
''This article refers to the cardinal direction; for other uses see West (disambiguation).

..... Click the link for more information.
EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001. Their greatest hit, their debut single "time after time", peaked at #13 in the Oricon singles chart.
..... Click the link for more information.
geocentric model of the universe is the disproven theory that the Earth is at the center of the universe and the Sun and other objects go around it. Belief in this system was common in ancient Greece.
..... Click the link for more information.
This article or section is in need of attention from an expert on the subject.
Please help recruit one or [ improve this article] yourself. See the talk page for details.
..... Click the link for more information.
satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.
..... Click the link for more information.
Sunset, also called sundown in some American English dialects, is the time at which the Sun disappears below the horizon in the west. It should not be confused with dusk, which is the point at which darkness falls, some time after the beginning of twilight when the Sun
..... Click the link for more information.
For other uses, see Daylight (disambiguation).
Daylight or the light of day is the combination of all direct and indirect sunlight outdoors during the daytime (and perhaps twilight).
..... Click the link for more information.
Night or nighttime is the period of time when the sun is below the horizon. The opposite of night is day (or "daytime" to distinguish it from "day" as used for a 24-hour period). Time of day varies based on factors such as season, latitude, longitude and timezone.
..... Click the link for more information.
The sunrise equation as follows can be used to derive the time of sunrise and sunset for any solar declination and latitude in terms of local solar time when sunrise and sunset actually occur:

cos(ωo) = -tan(φ)×tan(δ)

..... Click the link for more information.
The Sun

Observation data
Mean distance
from Earth 1.4961011 m
(8.31 min at light speed)
Visual brightness (V) −26.74m [1]
Absolute magnitude 4.
..... Click the link for more information.
Northern Hemisphere or northern hemisphere[1] is the half of a planet that is north of the equator—the word hemisphere literally means 'half ball'. It is also that half of the celestial sphere north of the celestial equator.
..... Click the link for more information.
Winter is one of the four seasons of temperate zones. Almost all English-language calendars, going by astronomy, state that winter begins on the winter solstice, and ends on the spring equinox.
..... Click the link for more information.
solstice occurs twice a year, whenever Earth's axis tilts the most toward or away from the Sun, causing the Sun to be farthest north or south at noon. The name is derived from Latin sol (sun) and sistere
..... Click the link for more information.
December 21 is the 1st day of the year (2nd in leap years) in the Gregorian calendar. There are 0 days remaining.
..... Click the link for more information.
Summer is one of the four seasons of the year. In the West, the seasons are generally considered to start at the equies and solstices, based on astronomical reckoning. In English-language calendars, based on astronomy, summer begins on the day of the summer solstice and ends on the
..... Click the link for more information.
June 21 is the 1st day of the year (2nd in leap years) in the Gregorian calendar. There are 0 days remaining.

In common years it is always in ISO week 25.
..... Click the link for more information.
equator is an imaginary line on the Earth's surface equidistant from the North Pole and South Pole. It thus divides the Earth into a Northern Hemisphere and a Southern Hemisphere. The equators of other planets and astronomical bodies are defined analogously.
..... Click the link for more information.
Noon is 12:00 at midday. Contrary to popular belief, it is not the moment when the sun crosses the meridian. The sun does cross the meridian at noon, apparent solar time, but we live by civil time (which is either Standard Time or Daylight Saving Time depending on the time
..... Click the link for more information.
analemma (pronounced IPA: /ˌænəˈlɛmə/, Latin for the pedestal of a sundial) is a curve representing the angular offset of a celestial body (usually the Sun) from its mean position
..... Click the link for more information.
Color or colour[1] (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, black, etc.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter