Tropic of Cancer

The Tropic of Cancer, which is also referred to as the Northern tropic, is the circle of latitude on the Earth that serves as a marker for the most northerly position at which the sun may appear directly overhead at its zenith. This event happens once per year, at the time of the June solstice, when the Northern Hemisphere is tilted towards the Sun to its maximum degree.

Its Southern Hemisphere counterpart, marking the most southerly position at which the Sun might appear directly overhead, is the Tropic of Capricorn. These tropics are two out of five major degree measures or major circles of latitude that mark the maps of the Earth, besides the Arctic and Antarctic Circles and the Equator. The locations of these circles of latitude are determined by the tilt of the Earth’s axis of rotation relative to the plane of its orbit.

It is named the Tropic of Cancer due to when the Sun reaches the zenith at this latitude, it’s entering the tropical sign of Cancer.

This Tropic of Cancer presently lies 23 degrees 26’ 16” north of the Equator. The position isn’t fixed, but it varies in a complicated manner over time. Currently, it is drifting southwards at the rate of almost half a second of latitude per year.

The climate of the Tropic of Cancer, excluding the cooler highland regions in China, is mostly hot and dry except for easterly coastal areas where orographic rainfall has the potential to be very heavy. The majority of the regions on the Tropic of Cancer experience two distinct seasons: an extremely hot summer with the temperatures frequently reaching 113 degrees F and a warm winter with the maximum at approximately 72 degrees F. Most land that is on or near the Tropic of Cancer is part of the Sahara Desert, while eastwards, the climate is torrid monsoonal with a short wet season from June to September with very little rainfall for the rest of the year.

Image Caption: World map with equator in SVG format and with a small red line so that it doesn’t hide Taiwan. Credit: WikiLaurent/Wikipedia  (CC BY-SA 3.0)