Tropic of Capricorn

The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the

subsolar point

at the December (or southern)

solstice

. It is thus the southernmost latitude where the Sun can be seen directly overhead. It also reaches 90 degrees below the horizon at solar midnight on the June Solstice. Its northern equivalent is the

Tropic of Cancer

.

The Tropic of Capricorn is one of the five major circles of latitude marked on maps of

Earth

. Its latitude is currently south of the

Equator

, but it is very gradually moving northward, currently at the rate of 0.47 arcseconds, or 15 metres, per year.

Less than 3% of the world's population lives south of it; this is equivalent to about 30% of the population of the

Southern Hemisphere

.

Name

When this line of latitude was named in the last centuries BC, the Sun was in the

constellation

Capricornus

at the December solstice. This is the date each year when the Sun reaches zenith at this latitude, the southernmost latitude it reaches for the year. (Due to the precession of the equinoxes the Sun currently appears in Sagittarius at this solstice.)

Geography and environment

The Tropic of Capricorn is the dividing line between the Southern Temperate Zone to the south and the tropics to the north. The

Northern Hemisphere

equivalent of the Tropic of Capricorn is the

Tropic of Cancer

.

The Tropic of Capricorn's position is not fixed, but constantly changes because of a slight wobble in the Earth's longitudinal alignment relative to its orbit around the Sun. Earth's axial tilt varies over a 41,000 year period from 22.1 to 24.5 degrees and currently resides at about 23.4 degrees. This wobble means that the Tropic of Capricorn is currently drifting northward at a rate of almost half an arcsecond (0.468″) of latitude, or 15 metres, per year (it was at exactly 23° 27′S in 1917 and will be at 23° 26'S in 2045). Therefore distance between

Arctic Circle

and Tropic of Capricorn is essentially constant moving in tandem. See under circles of latitude for information.

There are approximately 13 hours, 35 minutes of daylight during the summer solstice. During the winter solstice, there are 10 hours, 41 minutes of daylight. The length of the Tropic of Capricorn at 23°26′11.7″S is 36,788 km (22,859 mi).

Africa

In most of this belt of southern Africa, a minimum of seasonal rainfall is reliable and farming is possible, though yields struggle to compete with for example the Mississippi basin, even against like-to-like soil

fertiliser

s. Rivers have been successfully dammed particularly flowing from relief precipitation areas (high emininences) and those from the edge of the

Great Rift Valley

, such as the

Zambezi

, well within the Tropics. This, with alluvial or enriched soil, enables substantial yield grain farming in areas with good soil. Across this large region pasture farming is widespread, where intensive, brief and rotational it helps to fertilise and stabilise the soil, preventing run-off and desertification. This approach is traditional to many tribes and promoted by government advisors such as

Allan Savory

, a Zimbabwean-born biologist, farmer, game rancher, politician and international consultant and co-founder of the Savory Institute. According to the

United Nations University

Our World dissemination he is credited with developing “holistic management” in the 1960s and has led anti-desertification efforts in Africa for decades using a counterintuitive approach to most developed economies of increasing the number of livestock on grasslands rather than fencing them off for conservation. Such practices in this area have seen success and won generous awards; he gave the keynote speech at UNCCD's Land Day in 2018, and later that year a TED (conference) address, widely re-broadcast.

Australia

In

Australia

, areas around the Tropic have some of the world's most variable

rain

fall. In the east advanced plants such as flowering shrubs and

eucalyptus

and in most bioregions grasses have adapted to cope with means such as deep roots and little

transpiration

. Wetter areas, seasonally watered, are widely pasture farmed. As to animals, birds and marsupials are well-adapted. Naturally difficult

arable agriculture

specialises in dry fruits, nuts and modest water consumption produce. Other types are possible given reliable irrigation sources and, ideally, water-retentive enriched or alluvial soils, especially wheat; shallow irrigation sources very widely dry up in and after

drought

years. The multi-ridge

Great Dividing Range

brings relief precipitation enough to make hundreds of kilometres either side cultivable, and its rivers are widely dammed to store necessary water; this benefits the settled areas of New South Wales and

Queensland

.

Behind the end of the green hills, away from the

Pacific

, which is subject to warm, negative phases of the El Niño–Southern Oscillation (colloquially this is an "El Niño year/season") is a white, red and yellow landscape of 2,800 to 3,300 kilometres of

rain shadow

heading west in turn feature normally arid cattlelands of the

Channel Country

, the white Kati Thanda-Lake Eyre National Park, the mainly red Mamungari Conservation Park, then the Gibson Desert, after others the dry landscape settlement of

Kalbarri

on the west coast and its rest, northward. The

Channel Country

features an arid landscape with a series of ancient flood plains from rivers which only flow intermittently. The principal rivers are

Georgina River

, Cooper Creek and the Diamantina River. In most years, their waters are absorbed into the earth or evaporate, but when there is sufficient rainfall in their catchment area, these rivers flow into

Lake Eyre

, South Australia. One of the most significant rainfall events occurred in 2010 when a monsoonal low from ex- Cyclone Olga created a period of exceptional rainfall.

El Niño adverse phases cause a shift in atmospheric circulation; rainfall becomes reduced over Indonesia and Australia, rainfall and tropical cyclone formation increases over the tropical Pacific. The low-level surface trade winds, which normally blow from east to west along the equator, either weaken or start blowing from the other direction.

South America

In

South America

, whilst in the continental cratons soils are almost as old as in Australia and Southern Africa, the presence of the geologically young and evolving

Andes

means that this region is on the western side of the subtropical anticyclones and thus receives warm and humid air from the

Atlantic Ocean

. As a result, areas in

Brazil

adjacent to the Tropic are impressively productive agricultural regions, producing large quantities of crops such as

sugarcane

, and the natural

rainforest

vegetation has been almost entirely cleared, except for a few remaining patches of

Atlantic Forest

. Further south in

Argentina

, the temperate grasslands of the

Pampas

region is equally influential in

wheat

,

soybeans

,

maize

, and

beef

, making the country one of the largest worldwide agricultural exporters, similar to the role played by the

Prairies

region in

Canada

.

West of the Andes which creates a

rain shadow

air is further cooled and dried by the cold Humboldt Current which makes it very arid, creating the

Atacama Desert

, one of the driest in the world, so that no

glacier

s exist between Volcán Sajama at 18˚30'S and

Cerro Tres Cruces

at 27˚S.

Vegetation

here is almost non-existent, though on the eastern slopes of the Andes rainfall is adequate for rainfed agriculture.

Around the world

Starting at the

Prime Meridian

and heading eastwards, the Tropic of Capricorn passes through 10 countries:

:

Places located along the Tropic of Capricorn

The following cities and landmarks are either located near the Tropic of Capricorn, or the tropic passes through them.

;; Argentina
*

Andes Mountains

* The Chaco
* San Salvador de Jujuy

;; Australia
* Paraburdoo, Western Australia
* Newman, Western Australia
* Lake Disappointment, Western Australia
* Gibson Desert, Western Australia
* Ikuntji (Haast's Bluff), Northern Territory
* Alice Springs, Northern Territory
* Amaroo, Queensland
* Longreach,

Queensland

*

Great Dividing Range

,

Queensland

* Emerald, Queensland
* Gracemere,

Queensland

*

Rockhampton, Queensland

* Cape Capricorn,

Queensland

;; Botswana
* Kalahari Desert
* Khutse Game Reserve
* Kule
*

Mahalapye

;; Brazil
* Amambai
* Araçariguama
* Itaquaquecetuba
* Mogi das Cruzes
* Maringá
* Sorocaba
* Santana de Parnaíba
* São Paulo-Guarulhos International Airport
* São Paulo (Tremembé (district of São Paulo), Tremembé)
* São Roque, São Paulo, São Roque
* Guarulhos
* Taguaí
* Ubatuba

;; Chile
*

Atacama Desert

*

Andes Mountains

* Antofagasta

;; Madagascar
* Toliara

;; Mozambique
* Inhambane
* Morrumbene
* Massinga

;; Namibia
* Walvis Bay
* Swakopmund
* Namib Desert

;; Paraguay
* Concepción, Paraguay, Concepción

;; South Africa
* Kruger National Park
* Polokwane
* Capricorn District Municipality

List of countries entirely south of the Tropic of Capricorn

As most of earth's land is in the

Northern Hemisphere

only four countries are wholly south of the Tropic of Capricorn (which contrasts with 73, about one third of the current total, wholly north of the

Tropic of Cancer

):
* Eswatini (formerly Swaziland)
* Lesotho
* New Zealand
* Uruguay

See also

* Circle of latitude
**

Arctic Circle

**

Tropic of Cancer

**

Equator

** 23rd parallel south
** 24th parallel south
** Antarctic Circle
* Axial tilt#Values, Axial tilt
* Milankovitch cycles
*

Capricornus

Note

References

External links

Temporal Epoch Calculations


See: Obliquity of the ecliptic

{{DEFAULTSORT:Tropic Of Capricorn
Circles of latitude, S23
Tropics

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pl:Zwrotnik (geografia)