Circle of latitude

Circles of latitude parallel to the equatorial plane in the east-west direction running circles on the ( idealized ) surface β are constant latitude. In the Navigation doctrine of " latitude " is fachsprachlich called parallel of latitude.

Introduction

While the parallels of latitude perpendicular meridians are all great circles are the circles of latitude generally small circles - up to the equator, which divides as zero latitude the earth into a northern and a southern hemisphere. Other special circles of latitude are the tropics and the polar circles, which become important for the Sun in the course of the seasons by the obliquity of the ecliptic. The definition of the climate zones refers to certain parallels.

The distance between two latitude circles with a width difference of one degree on average is approximately 111 km, but less than in the extreme northern and southern latitudes because the Earth flattening near the equator. A similar error would have to calculate the length of the parallels as 2πR cos β constant earth radius R.

Special parallels

  • 90 degrees north: Geographical North Pole, circle to the point reduced
  • 66.56 degrees North: Polar Circle
  • 23.44 degrees North: Tropic of Cancer, Tropic of Cancer
  • 0 degrees: Equator, Latitude 0, the only latitude, the great circle is the same
  • 23.44 degrees South: Southern Tropic, Tropic of Capricorn
  • 66.56 degrees South: Antarctic Polar Circle
  • 90 degrees South: Geographical South Pole, circle to the point of reduced

Because of precession and nutation of the Earth's axis parallel to the polar circles and the tropics are variable.

Circles of latitude as borders

Parallels are often used as a border between countries or regions, especially in North America and in the colonies.

  • 49 degrees North: part of the border between Canada (N) and the U.S. ( S)
  • 45 degrees north: border between Canada (N) and Vermont ( S), the border between Montana ( N) and Wyoming ( S)
  • 42 degrees north: border between Oregon ( N) and California (S ), part of the border between New York (N) and Pennsylvania ( S)
  • 41 degrees North: part of the border between Colorado, Utah ( S), Wyoming and Nebraska ( N)
  • 40 degrees north: border between Nebraska ( N) and Kansas ( S)
  • 39.7 degrees North: Eastern part of the historic border between the states with the prohibition of slavery in the northern United States and the slave-holding states in the South ( Mason - Dixon line as a border to the east course of the Mississippi)
  • 38 degrees north: the border between North and South Korea in 1945
  • 37 degrees north: border between Utah, Colorado and Kansas ( N) as well as Arizona, New Mexico and Oklahoma ( S)
  • 36.5 degrees North: Western part of the historic border between the states with the prohibition of slavery in the northern United States and the slave-holding states in the South ( border line west of the Mississippi in accordance with the Missouri Compromise )
  • 35 degrees north: border between Tennessee ( N) as well as Mississippi, Alabama and Georgia ( S)
  • 32 degrees North: part of the border between New Mexico ( N) and Texas ( S)
  • 22 degrees North: part of the border between Egypt (N) and the Sudan ( S)
  • 26 degrees South: part of the border between the Northern Territory and Queensland (N) and South Australia ( S)
Circle of a sphere Northern Hemisphere Cancer (constellation) Capricornus Axial tilt#Obliquity of the ecliptic .28Earth.27s axial tilt.29 Georgia (U.S. state)
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