Latitude

Latitude, sometimes denoted by the Greek letter φ, gives the location of a place on Earth north or south of the Equator.

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A region's latitude has a great effect on its climate and weather.

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Latitude is an angular measurement ranging from 0? at the Equator to 90? at the poles ( 90? N or 90? S).

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Other latitudes of particular importance are the Tropic of Cancer (latitude 23?27′ north), the Tropic of Capricorn (latitude 23?27′ south), the Arctic Circle (latitude 66?33′ north), and the Antarctic Circle (latitude 66?33′ south). Only at latitudes between the Tropics is it possible for the sun to be at the zenith. Only north of the Arctic Circle or south of the Antarctic Circle is the midnight sun possible.

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All locations of a given latitude are collectively referred to as a line of latitude or parallel, because they are coplanar, and all such planes are parallel to the Equator. Lines of latitude other than the Equator are approximately small circles on the surface of the Earth; they are not geodesics since the shortest route between two points at the same latitude involves moving farther away from the equator.

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Latitude more loosely determines tendencies in climate, polar auroras, prevailing winds, and other physical characteristics of geographic locations.

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Each degree of latitude is further sub-divided into 60 minutes, each of which divided into 60 seconds. A latitude is thus specified as 13° 19′ 42" N. For high accuracy, the seconds are specified with a decimal fraction. An alternative representation uses degrees and minutes, where parts of a minute are expressed as a decimal fraction, thus: 13° 19.717′ N. Degrees expressed as a decimal number (Decimal Degree notation) is more often used: 13.32861° N. Sometimes, the North/South suffix is replaced by a negative sign for South (-90? for the south pole).

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A specific latitude may then be combined with a specific longitude to give a precise position on the Earth's surface.

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One minute of arc of latitude is approximately one nautical mile or 1852 metres.

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Colatitude is the complement of latitude.

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Because the Earth is slightly flattened by its rotation, cartographers refer to a variety of auxiliary latitudes to precisely adapt spherical projections according to their purpose. In common usage "latitude" refers to geodetic or geographic latitude φ and is the angle between the equatorial plane and a line that is normal to the reference spheroid, which approximates the shape of the Earth to account for flattening of the poles and bulging of the equator. The geocentric latitude is the angle between the equatorial plane and a line from the center of the Earth. A more obscure measure of latitude is the astronomical latitude, which is the angle between the equatorial plane and the normal to the geoid (ie a plumb line). It originated as the angle between horizon and pole star.

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The expressions following assume elliptical polar sections with eccentricity e, and that all sections parallel to the equatorial plane are circular. Geographic latitude (with longitude) then provides a Gauss map.

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Geocentric latitude φg is probably what's generally thought to be meant by latitude. It is the angle between the plane of the equator and the radial line.

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: anphi_g=(1-e^2) anphi

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For other planets such as Mars, geographic and geocentric latitude are called "planetographic" and "planetocentric" latitude, respectively. Most maps of Mars since 2002 use planetocentric coordinates.

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Equator: The equator is an imaginary circle drawn around a planet (or other astronomical object) at a distance halfway between the poles. The equator divides the planet into a Northern Hemisphere and the Southern Hemisphere. The latitude of the equator is, by definition, 0°. The length of Earth's equator...

Climate: The climate (ancient Greek: κλίμα) is the weather averaged over a long period of time. A descriptive saying is that "climate is what you expect, weather is what you get." The Intergovernmental Panel on Climate Change (IPCC) glossary definition is:...

Weather: Weather comprises all the various phenomena that occur in the atmosphere of a planet. "Weather" is normally taken to mean the activity of these phenomena over a period of a few days. The average weather over a longer period is known as the climate. This aspect of the weather is studied with great in...