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Tropical Climate

Tropical climate

The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the northern hemisphere and the Tropic of Capricorn in the southern hemisphere. This area lies approximately between 23°30'/23.5° N latitude and 23°30'/23.5° S latitude, and includes all the parts of the Earth where the sun reaches a point directly overhead at least once during the solar year. (In the temperate zones, north of the Tropic of Cancer and south of the Tropic of Capricorn, the sun never reaches an altitude of 90° or directly overhead.) The word "tropics" comes from Greek tropos meaning "turn", because the apparent position of the Sun oscillates between the two tropics with a period that defines the average length of a year. Tropical plants and animals are those species native to the tropics. Tropical is also sometimes used in a general sense of a place that is warm and moist year-round, often with the sense of lush vegetation. However, there are places in the tropics that are anything but "tropical" in this sense, with even alpine tundra and snow-capped peaks, including Mauna Kea, Mt. Kilimanjaro, and the Andes as far south as the northernmost parts of Chile and Argentina. In Köppen's scheme of climate classification, a tropical climate is defined as a non-arid climate in which all twelve months have mean temperatures above 18 °C (64.4 °F).

Examples of tropical cities

- Bombay, India (19.1º N)
- Hong Kong, Hong Kong SAR, People's Republic of China (22.3º N)
- Rio de Janeiro, Brazil (22.9º S)
- Singapore (1.4º N)
- Manila, Philippines (14.6º N)
- Cairns, Queensland, Australia (16.7º S)

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 is about 40,075.0 km, or 24,901.5 miles. The equator is one of the five main circles of latitude based on the relationship of the Earth's rotation and plane of orbit around the sun. Additionally, the equator is the only line of latitude which is also a great circle The Sun, in its seasonal movement through the sky, passes directly over the equator twice each year on the Vernal and Autumnal Equinoxes, which occur in March and September (respectively). At the equator, the rays of the sun are perpendicular to the surface of the earth on these dates. Places near the equator experience the quickest rates of sunrise and sunset in the world, taking minutes. Such places also have a relatively constant amount of day/night time on every day throughout the year compared with more northerly or southerly places.

Equatorial climate

In many tropical regions people identify two seasons, wet and dry, but most places very close to the equator are wet throughout the year, although seasons can vary depending on a variety of factors including elevation and proximity to an ocean. ocean The surface of the Earth at the equator is mainly ocean. The highest point on the Equator is 4,690 m, at 77° 59' 31" W on the south slopes of Volcán Cayambe (summit 5,790 m) in Ecuador. This is a short distance above the snow line, and is the only point on the Equator where snow lies on the ground (Google Earth satellite data and photos).

Equatorial countries

The equator traverses the land and/or water of 13 countries in total:
- São Tomé and Príncipe - passing through Ilhéu das Rolas, an islet in this archipelago
- Gabon
- Republic of the Congo
- Democratic Republic of Congo
- Uganda
- Kenya
- Somalia
- Maldives - misses every island, passing between Gaafu Dhaalu Atoll and Gnaviyani Atoll
- Indonesia
- Sumatra - also small islands Tanah Masa to the West and Lingga to the East
- Borneo - Kalimantan
- Sulawesi
- Halmahera - also small islands Kayoa to the West and Gebe to the East
- Kawe, a small island near Waigeo - and other islets throughout Indonesia
- Kiribati - misses every island
- Gilbert Islands - passing between Aranuka and Nonouti Atolls
- Line Islands - passing between Kiritimati Island and Malden Island, though neither is very close to the equator
- Ecuador
- Galapagos Islands - passing through Isabela Island.
- Mainland Ecuador
- Colombia
- Brazil

Tropic of Cancer

:Tropic of Cancer is also the name of a novel by Henry Miller, first published in 1934. 1934 The Tropic of Cancer (cancer (♋) is Latin for crab), one of the five major circles of latitude that mark maps of the Earth, is the parallel of latitude that lies 23° 26' 22" north of the Equator. The line is called the Tropic of Cancer because when it was named, the sun was in the constellation of Cancer when it appeared directly overhead at this latitude during the June solstice. However, due to precession of the equinoxes, the June solstice is now in the constellation Taurus. It is the farthest northern latitude at which the sun can appear directly overhead. North of this line is the Northern Temperate Zone. The Tropic of Capricorn is at the opposite latitude south of the Equator. South of the Tropic of Cancer and north of the Tropic of Capricorn are the Tropics. According to Fédération Aéronautique Internationale's rules, to qualify as a circumnavigation, a flight must be no less than the length of Tropic of Cancer (36,787.559 km), as well as cross all meridians and end on the same airfield where it started. Category:Lines of latitude

Tropic of Capricorn

:Tropic of Capricorn is also the name of a novel by Henry Miller, first published in 1939. 1939 The Tropic of Capricorn is one of the five major circles of latitude that mark maps of the Earth. It is the parallel of latitude at 23° 26' 22" south of the Equator, and is the farthest southern latitude that the sun can appear directly overhead, occurring on the December solstice. Its northern hemisphere equivalent is the Tropic of Cancer. Latitudes south of the Tropic of Capricorn are in the Southern Temperate Zone. North of this line are the Tropics. It is called the Tropic of Capricorn because when it was named about 2000 years ago, the sun was entering the constellation Capricorn on the December solstice. Now, the sun appears in the constellation Sagittarius during this time. The change is due to precession of the equinoxes. Category:Lines of latitude

Altitude

For other uses see Altitude (disambiguation) Altitude is the elevation of an object from a known level or datum, called zero level. Most often this level is defined as the absolute sea level, but it can vary. In aviation, the term altitude is used to describe elevation above mean sea level, the term height refers to elevation above a ground reference point and the term flight level is the elevation according to a standard pressure altimeter setting. Atmospheric pressure decreases with altitude. In North America and the UK altitude is usually measured in feet. Everywhere else in the world the altitude is measured in metres.
- High altitude = 1500m – 3500m
- Very High altitude = 3500m – 5500m
- Extreme altitude = 5500m – above
- Troposphere — 8 km (above poles) – 18 km (above equator).
- Tropopause
- Stratosphere — 10km (above poles) 50 km (above equator),contains the Ozone layer
- Mesosphere — 50 km – 80 km
- Thermosphere — 100–200 km (1000°–1500° K)
- Exosphere — 500 km – 10,000km (outer space)

Altitude records

- 19 September, 1783 — 500m (1,700ft) animal carrying Montgolfier hot-air balloon.
- 15 October, 1783 — 26m (84ft) Pilâtre de Rozier in a Montgolfier tethered balloon.
- 1 December, 1783 — 2.7km Professor Charles and assistant Robert in Charliere, his hydrogen-filled balloon.
- 1784 — 4km Pilâtre de Rozier and the chemist Proust in a Montgolfier.
- 18 July, 1803 — 7.28km Etienne Gaspar Robertson and Lhoest in a balloon.
- 1839 — 7.9km Charles Green and Spencer Rush in a free balloon.
- 5 September, 1862 — 9km Coxwell and English physicist Glaisher in a balloon.
- 4 December, 1894 — 9.155km German meteorologist Berson in an airship.
- 31 July, 1901 — 10.8km German meteorologist Berson and Süring in a free balloon.

Year

A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. By extension, this can be applied to any planet: for example, a "Martian year" is a year on Mars.

Seasonal year

A seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.

Calendar year

A calendar year is the time between two dates with the same name in a calendar. Solar calendars usually aim to predict the seasons, but because the length of individual seasonal years varies significantly, they instead use an astronomical year as a surrogate. For example, the ancient Egyptians used the heliacal rising of Sirius to predict the flooding of the Nile. The Gregorian calendar aims to keep the vernal equinox on or close to March 21; hence it follows the vernal equinox year. The average length of its year is 365.2425 days. No astronomical year has an integer number of days or months, so any calendar that follows an astronomical year must have a system of intercalation such as leap years. In the formerly used Julian calendar, the average length of a year was 365.25 days. This is still used as a convenient time unit in astronomy, see below.

Astronomical years

Julian year

The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" (symbol "a" from the Latin annus, annata) used in various scientific contexts. The Julian century of 36525 days and the Julian millennium of 365250 days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive.

Sidereal year

The sidereal year is the time for the Earth to complete one revolution of its orbit, as measured in a fixed frame of reference (such as the fixed stars, Latin sidus). Its duration in SI days of 86,400 SI seconds each is on average: :365.256 363 051 days (365 d 6 h 9 min 9 s) (at the epoch J2000.0 = 2000 January 1 12:00:00 TT).

Tropical year

A tropical year is the time for the Earth to complete one revolution with respect to the framework provided by the intersection of the ecliptic (the plane of the orbit of the Earth) and the plane of the equator (the plane perpendicular to the rotation axis of the Earth). Because of the precession of the equinoxes, this framework moves slowly westward along the ecliptic with respect to the fixed stars (with a period of about 26,000 tropical years); as a consequence, the Earth completes this year before it completes a full orbit as measured in a fixed reference frame. Therefore a tropical year is shorter than the sidereal year. The exact length of a tropical year depends on the chosen starting point: for example the vernal equinox year is the time between successive vernal equinoxes. The mean tropical year (averaged over all ecliptic points) is: :365.242 189 67 days (365 d 5 h 48 min 45 s) (at the epoch J2000.0).

Anomalistic year

The anomalistic year is the time for the Earth to complete one revolution with respect to its apsides. The orbit of the Earth is elliptical; the extreme points, called apsides, are the perihelion, where the Earth is closest to the Sun (January 2 in 2000), and the aphelion, where the Earth is farthest from the Sun (July 2 in 2000). Because of gravitational disturbances by the other planets, the shape and orientation of the orbit are not fixed, and the apsides slowly move with respect to a fixed frame of reference. Therefore the anomalistic year is slightly longer than the sidereal year. It takes about 112,000 years for the ellipse to revolve once relative to the fixed stars. The anomalistic year is also longer than the tropical year (which calendars attempt to track) and so the date of the perihelion gradually advances every year. It takes about 21,000 years for the ellipse to revolve once relative to the vernal equinox, thus for the date of perihelion to return to the same place (given a calendar that tracks the seasons perfectly). The average duration of the anomalistic year is: :365.259 635 864 days (365 d 6 h 13 min 52 s) (at the epoch J2000.0).

Draconic year

The draconitic year, eclipse year or ecliptic year is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the same lunar node (a point where the Moon's orbit intersects the ecliptic). This period is associated with eclipses: these occur only when both the Sun and the Moon are near these nodes; so eclipses occur within about a month of every half eclipse year. Hence there are two eclipse seasons every eclipse year. The average duration of the eclipse year is: :346.620 075 883 days (346 d 14 h 52 min 54 s) (at the epoch J2000.0). :This term is sometimes also used to designate the time it takes for a complete revolution of the Moon's ascending node around the ecliptic: 18.612 815 932 years (6798.331 019 days).

Fumocy

The full moon cycle or fumocy is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the perigee of the Moon's orbit. This period is associated with the apparent size of the full moon, and also with the varying duration of the anomalistic month. The duration of one full moon cycle is: :411.784 430 29 days (411 d 18 h 49 min 34 s) (at the epoch J2000.0).

Heliacal year

A heliacal year is the interval between the heliacal risings of a star. It equals the sidereal year only if the star is on the ecliptic. It differs from the sidereal year for stars north or south of the ecliptic because of the significant angle (23.5°) between Earth's celestial equator and the ecliptic.

Sothic year

The Sothic year is the interval between heliacal risings of the star Sirius. Its duration is very close to the mean Julian year of 365.25 days.

Gaussian year

The Gaussian year is the sidereal year for a planet of negligible mass (relative to the Sun) and unperturbed by other planets that is governed by the Gaussian gravitational constant. Such a planet would be slightly closer to the Sun than Earth's mean distance. Its length is: :365.256 898 3 days (365 d 6 h 9 min 56 s).

Besselian year

The Besselian year is a tropical year that starts when the fictitious mean Sun reaches an ecliptic longitude of 280°. This is currently on or close to 1 January. It is named after the 19th century German astronomer and mathematician Friedrich Bessel. An approximate formula to compute the current time in Besselian years from the Julian day is: :B = 2000 + (JD - 2451544.53)/365.242189

Great year

The Great year, Platonic year, or Equinoctial cycle corresponds to a complete revolution of the equinoxes around the ecliptic. Its length is approximately 25,770.639 22 years (9,412,725 d 23 h 22 min).

Variation in the length of the year and the day

The exact length of an astronomical year changes over time. The main sources of this change are: #The precession of the equinoxes changes the position of astronomical events with respect to the apsides of Earth's orbit. An event moving toward perihelion recurs with a decreasing period from year to year; an event moving toward aphelion recurs with an increasing period from year to year. #The gravitational influence of the Moon and planets changes the shape of the Earth's orbit. Tidal drag between the Earth and the Moon and Sun increases the length of the day and of the month. This in turn depends on factors such as continental rebound and sea level rise. It is also suspected that changes in the effective mass of the sun, caused by nuclear fusion, could have a significant impact on the earth year over time.

Summary of various kinds of year

- 353, 354 or 355 days — the lengths of regular years in some lunisolar calendars
- 354.37 days — 12 lunar months; the average length of a year in lunar calendars
- 365 days — a common year in many solar calendars; ~31.53 million seconds
- 365.24219 days — a mean tropical year near the year 2000
- 365.2424 days — a vernal equinox year.
- 365.2425 days — the average length of a year in the Gregorian calendar
- 365.25 days — the average length of a year in the Julian calendar; the light year is based on it; it is 31,557,600 seconds
- 365.2564 days — a sidereal year
- 366 days — a leap year in many solar calendars; 31.62 million seconds
- 383, 384 or 385 days — the lengths of leap years in some lunisolar calendars
- 383.9 days — 13 lunar months; a leap year in some lunisolar calendars An average Gregorian year is 365.2425 days = 52.1775 weeks, 8,765.82 hours = 525,949.2 minutes = 31,556,952 seconds (mean solar, not SI). A common year is 365 days = 8,760 hours = 525,600 minutes = 31,536,000 seconds. A leap year is 366 days = 8,784 hours = 527,040 minutes = 31,622,400 seconds. An easy to remember approximation for the number of seconds in a year is

\begin\pi\end

×10⁷ seconds. The 400-year cycle of the Gregorian calendar has 146097 days and hence exactly 20871 weeks. See also Numerical facts about the Gregorian calendar.

Mauna Kea

Mauna Kea is a dormant volcano in the Hawaiian Islands, one of five volcanic peaks that together form the Island of Hawaii. In Hawaiian, mauna kea means "white mountain", a reference to the fact that it is regularly snow or frost capped during the northern hemisphere winter. Its highest point, Pu'u Wēkiu (one of numerous cinder cones on the summit), is the highest point in the state of Hawaii at 13,796 ft (4,208m). Mauna Kea is also the tallest mountain in the world when measured from base to peak, its base being some 16,000 ft (over 5,000 m) under the surface of the Pacific Ocean. After millions of years of building itself up by volcanic activity, the mountain's height is slowly decreasing as it is being crushed under its own massive weight into the Pacific seafloor. Although snow and ice occur now mostly in the period from November through March, Mauna Kea had permanent (year-round) ice caps during the Pleistocene ice ages. (Woodcock et al., 1970) The summit shows evidence of four periods of glaciation over the last 200,000 years, the last ending about 11,000 years ago. The elevation and location of Mauna Kea have made it an important location for atmospheric and astronomical observations. The summit is above approximately 40% of Earth's atmosphere and 90% of the water vapor, allowing for exceptionally clear images. Additionally, the peak is well above the inversion layer, allowing up to 300 clear nights per year. Also, at 20°N latitude, much of both the northern and southern skies are visible. Finally, the fact that it's a shield volcano has meant that road transportation to the summit is relatively easy. All of these factors have made Mauna Kea a prime target for state-of-the-art astronomy, and the summit is home to many different observatories.

References

- PMID 16057558

External links

- [http://hvo.wr.usgs.gov/volcanoes/maunakea/ USGS page about Mauna Kea] Category:Volcanoes of the Island of Hawaii Category:Hawaii mountains Category:Shield volcanoes ja:マウナ・ケア山 simple:Mauna Kea

Mount Kilimanjaro

Kilimanjaro is a mountain in northeastern Tanzania. It includes the highest peak in Africa. Although believed to be extinct by many, this volcano is very much active. Fumaroles emit gas in the crater on the main summit of Kibo. Scientists concluded in 2003 that molten lava is just 400 metres below the summit crater. Although new activity is not expected, there are fears the volcano may collapse, causing a major eruption similar to Mount St. Helens. Several collapses and landslides have occurred on Kibo in the past, one creating the area known as the western breach. Although there is no recorded history of eruptions, local legend speaks of activity around 170 years ago. The highest point is Uhuru Peak on the volcano Kibo, 5,895 metres. As the highest point in Africa, Uhuru Peak is one of the Seven Summits. The summit was first reached by the German Hans Meyer and Austrian Ludwig Purtscheller in 1889. Two other peaks are also extinct volcanoes: Mawenzi (5,149 metres), the third highest peak in Africa (after Mount Kenya) and Shira (3,962 m). An ascent of Mawenzi requires rock climbing and/or snow/ice climbing skills. The climb to Uhuru Peak is considered to be a relatively straightforward endeavour; however, ample time must still be provided for proper acclimatization to prevent altitude sickness. The three easiest routes, Marangu, Rongai and Machame can be climbed by a person of good health, and require no mountaineering experience. Many who climb employ altitude-sickness medication and find this to be helpful in preventing the pounding headaches that plague many travellers. Those who travel on the Marangu route usually take 4-5 days to complete their climb. Huts with cooking facilites, bathrooms, and (sometimes) electricity are available at each the end of each days' journey. The final part of the climb, from Kibo hut at 15,500 ft. to the summit, is generally undertaken at night, because the scree is frozen together, making the climb significantly easier. Gilman's Point, on the rim of the crater, but about 1 1/2 hours hike from Uhuru, is attained at 5:00 - 6:00 am; those who have the strength to continue may then hike on to Uhuru in the growing sunlight and rising temperatures. Another route is the Western Breach which is much more technical in nature. Annually, approximately 15,000 people attempt to climb the mountain, of whom 40% reach the summit. At the summit, there is a sign posted by the Tanzanian government. The sign (printed in English only) reads, in part, "Congratulations! You are now at Uhuru Peak, Tanzania, 5,895 m. AMSL". The sign is covered in travel stickers from past trekkers who have left their mark on the top of the peak. Due to the equatorial location as well as huge height, climbers can experience almost every climate type on earth during the journey to the top. Kilimanjaro is also the highest point in the world to be covered by a GSM mobile phone network. The service is provided by Vodacom.

Current conditions

Vodacom While the volcano appears to be dormant on the inside, it is the events that are taking place on top of the mountain that are drawing global attention recently. The snow cap that has covered the top of the mountain for the past 11,000 years since the last ice age is rapidly disappearing. Over the past century, the ice cap volume has dropped by more than 80%[http://svs.gsfc.nasa.gov/stories/kilimanjaro_20021216/index.html]. In 2002, many experts in the field predicted that within 15 years all of the snow on top of Africa's tallest peak would be gone. In March 2005, it was reported that the peak was now almost bare, for the first time in 11,000 years [http://www.guardian.co.uk/international/story/0,3604,1437549,00.html]. This is not due to any temperature changes, but is instead due to a lack of snowfall. It is thought that deforestation over the past century has led to a decrease in moisture reaching the summit and turning into snowfall. 2005

External links

- [http://researchnews.osu.edu/archive/kilicores.htm Ohio University study expedition to Kilimanjaro's glaciers]
- [http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=10856 NASA Earth Explorer page]
- [http://members.verizon.net/grfiv/Personal/Kilimanjaro.htm Climbing Kilimanjaro]
- [http://www.thisisthelife.com/en/amazing-views/kilimanjaro-africa.htm View from the top of Kilimanjaro]
- [http://www.seabhcan.com/travel_stories/kili_files/pan.html 360 Panoramic View from the top, with Map] Kilimanjaro Kilimanjaro Kilimanjaro Kilimanjaro Kilimanjaro ja:キリマンジャロ (山)

Andes

]] The Andes is a vast mountain system forming a continuous chain of highland along the western coast of South America. It is roughly 7000 km (4400 mi) long, 500 km (300 mi) wide in some parts (widest between 18° to 20° S latitude), and of an average height of about 4000 m (13,000 ft). The Andean range is composed of two great principal chains with a deep intermediate depression, in which, and at the sides of the great chains, arise other chains of minor importance, the chief of which is that called the Cordillera de la Costa of Chile. This starts from the southern extremity of the continent and runs in a northerly direction, parallel with the coast, being broken up at its beginning into a number of islands and afterwards forming the western boundary of the great central valley of Chile. To the north this coastal chain continues in small ridges or isolated hills along the Pacific Ocean as far as Venezuela, always leaving the same valley more or less visible to the west of the western great chain. The Andes is the highest mountain range outside Asia, with its highest peak, Aconcagua, rising to 6,982m above sea level. The summit of Mount Chimborazo in the Ecuadorean Andes is the point on the Earth's surface most distant from its centre, due to the equatorial bulge.

External links

- [http://www.photoglobe.info/db_merced/ PhotoGlobe: Andes around Mt. Mercedario]
- [http://www.geo.arizona.edu/geo5xx/geo527/Andes/intro.html Andes geology Arizona Edu.] Category:Mountain ranges Category:Mountains of South America ko:안데스 산맥 ja:アンデス山脈 simple:Andes

Argentina

Argentina is a country in South America, situated between the Andes in the west and the southern Atlantic Ocean in the east and south. It is bordered by Paraguay and Bolivia in the north, Brazil and Uruguay in the northeast, and Chile in the west and south. It also claims the British overseas territories of the Falkland Islands (known in Spanish the Islas Malvinas ) and South Georgia and the South Sandwich Islands. Under the name of Argentine Antarctica, it claims around 1,000,000 km² of Antarctica, overlapping other claims by Chile and the United Kingdom. By area, it is the second largest country of South America after Brazil and the 8th largest country in the world. The country is formally named República Argentina (Argentine Republic), while for purposes of legislation the form Nación Argentina (Argentine Nation) is used.

Origin and history of the name

The name Argentina derives from the Latin argentum (silver) and the first Spanish conquerors to the River Plate. Indigenous people gave silver gifts to the survivors of the shipwrecked expedition, who were led by Juan Díaz de Solís. The legend of Sierra del Plata — a mountain rich in silver — reached Spain around 1524. The Spaniards named the river of Solís, Río de la Plata (River of the Silver). The name Argentina was first used in Ruy Diaz de Guzman's 1612 book Historia del descubrimiento, población, y conquista del Río de la Plata (History of the discovery, population, and conquest of the River Plate), naming the territory Tierra Argentina (land of silver).

History

The area of present Argentina was relatively sparsely populated until it was colonised by Europeans. The Diaguita lived in northwestern Argentina on the edge of the expanding Inca Empire; the Guaraní lived farther east. Europeans arrived in 1502. Spain established a permanent colony on the site of Buenos Aires in 1580, and the Viceroyalty of the River Plate in 1776. Independence from Spain was declared on 9 July 1816. Centralist and federationist groups were in conflict, until national unity was established and the constitution promulgated in 1853. Foreign investment and immigration from Europe aided the introduction of modern agricultural techniques and integration of Argentina into the world economy in the late 19th century. In the 1880s the "Conquest of the Desert" subdued or exterminated the remaining native tribes of Patagonia. From 1880 to 1930 Argentina became one of the ten wealthiest nations. Conservative forces dominated Argentine politics until 1916, when their traditional rivals, the Radicals, won control of the government. The military forced Hipólito Yrigoyen from power in 1930 leading to another decade of Conservative rule. 1930, and the Antarctica, that overlaps both Chilean and British claims, though all three are signatory to the Antarctic Treaty]] Political change led to the presidency of Juan Perón in 1946, who aimed at empowering the working class and greatly expanded the number of unionised workers. The Revolución Libertadora of 1955 deposed him. In the 1950s and 1960s, military and civilian administrations traded power. When military governments failed to revive the economy and suppress escalating terrorism in the late 1960s and early 1970s, the way was open for Perón's return to the presidency in 1973, with his third wife, María Estela Isabel Martínez de Perón, as Vice President. During this period, extremists on the left and right carried out terrorist acts with a frequency that threatened public order. Perón died in 1974. His wife succeeded him in office, but a military coup removed her from office in 1976, and the armed forces formally exercised power through a junta in charge of the self-appointed National Reorganisation Process, until 1983. The armed forces repressed opposition using harsh illegal measures (the "Dirty War"); thousands of dissidents were "disappeared". Economic problems, charges of corruption, public revulsion in the face of human rights abuses and, finally, the country's 1982 defeat in the Falklands War discredited the Argentine military regime. Democracy was restored in 1983. Raúl Alfonsín's Radical government took steps intending to account for the "disappeared", establishing civilian control of the armed forces and consolidating democratic institutions. Failure to resolve endemic economic problems and an inability to maintain public confidence caused his early departure. President Carlos Menem imposed peso-dollar fixed exchange rate in 1991 to stop hyperinflation, and adopted far-reaching market-based policies, dismantling protectionist barriers and business regulations, and implementing a privatisation program. These reforms contributed to significant increases in investment and growth with stable prices through most of the 1990s. The Menem and de la Rúa administrations faced diminished competitiveness of exports, massive imports which damaged national industry and reduced employment, chronic fiscal and trade deficits, and the contagion of several economic crises. The Asian financial crisis in 1998 precipitated an outflow of capital that mushroomed into a recession, which led to a total freezing of the bank accounts (the corralito), and culminated in a financial panic in November 2001. Next month, amidst bloody riots, President de la Rúa resigned. Several new presidents followed in quick succession. Argentina defaulted on its international debt obligations. The peso's almost 12-year-old link with the dollar was abandoned, resulting in massive currency depreciation and inflation, in turn triggering a spike in unemployment and poverty. In 2003, Néstor Kirchner became the president, and started implementing new policies based on re-industrialisation, import substitution, increased exports, consistent fiscal surplus, and high exchange rate.

Politics

Néstor Kirchner The Argentine constitution of 1853, as revised in 1994, mandates a separation of powers into executive, legislative, and judicial branches at the national and provincial level. The president and vice president are directly elected to 4-year terms. Both are limited to two consecutive terms; they are allowed to stand for a third term or more after an interval of at least one term. The president appoints cabinet ministers, and the constitution grants him considerable power as both head of state and head of government, including authority to enact laws by presidential decree under conditions of "urgency and necessity" and the line-item veto. Argentina's parliament is the bicameral National Congress or Congreso de la Nación, consisting of a Senate (Senado) of 72 seats and a Chamber of Deputies (Cámara de Diputados) of 257 members. Since 2001, senators have been directly elected, with each province, including the Federal Capital, represented by three senators. Senators serve 6-year terms. One-third of the Senate stands for reelection every 2 years via a partial majority system in each district. Members of the Chamber of Deputies are directly elected to 4-year term via a system of proportional representation. Voters elect half the members of the lower house every 2 years. See also Argentinian Legal System

Administrative Divisions

Argentinian Legal System Argentina is divided into 23 provinces (provincias; singular: provincia), and 1 autonomous city (commonly known as capital federal), marked with an asterisk: ^- The current official name for the federal district is "Ciudad Autónoma de Buenos Aires". Buenos Aires has been the capital of Argentina since its unification, but there have been projects to move the administrative centre elsewhere. During the presidency of Raúl Alfonsín a law was passed ordering the move of the federal capital to Viedma, a city in the Patagonic province of Río Negro. Studies were underway when hyperinflation, in 1989, killed off the project. Though the law was never formally repealed, it has become a mere historical relic, and the project has been forgotten.

Urbanization

hyperinflation About 2.7 million people live in the Autonomous City of Buenos Aires, and roughly 11.5 million in Greater Buenos Aires (2001), making it one of the largest urban conglomerates in the world. Together with their respective metropolitan areas, the second and third largest cities in Argentina, Córdoba and Rosario, each comprise about 1.3 million inhabitants. Most European immigrants to Argentina (coming in great waves especially around the First and the Second World Wars) settled in the cities, which offered jobs, education, and other opportunities that enabled newcomers to enter the middle class. Since the 1930s many rural workers have moved to the big cities. The 1990s saw many rural towns become ghost towns when train services were abandoned and local products manufactured on a small scale were replaced by massive amounts of imported cheap goods, in part because of the monetary policy which kept the U. S. dollar exchange rate fixed and low. Many slums (villas miseria) sprouted in the outskirts of the largest cities, inhabited by empoverished low-class urban dwellers and migrants from smaller towns in the interior of the country. Argentina's urban areas have a European look, reflecting the influence of their European settlers. Many towns and cities are built like Spanish cities around a main square called a plaza. A cathedral and important government buildings often face the plaza. The general layout of the cities is called a damero, that is, a checkerboard, since it is based on a pattern of square blocks, though modern developments sometimes depart from it (for example, the city of La Plata, built at the end of the 19th century, is organised as a checkerboard plus diagonal avenues at fixed intervals). In descending order by number of inhabitants, the major cities in Argentina are Buenos Aires, Córdoba, Rosario, Mendoza, La Plata, Tucumán, Mar del Plata, Salta, Santa Fe, and Bahía Blanca. For a more comprehensive list, see List of cities in Argentina.

Geography

List of cities in Argentina Argentina can roughly be divided into three parts: the fertile plains of the Pampas in the central part of the country, the centre of Argentina's agricultural wealth; the flat to rolling plateau of Patagonia in the southern half down to Tierra del Fuego; and the rugged Andes mountain range along the western border with Chile, with the highest point being the Cerro Aconcagua at 6,960 m. Major rivers include the Paraguay, Bermejo, Colorado, Uruguay and the largest river, the Paraná. The latter two flow together before meeting the Atlantic Ocean, forming the estuary of the River Plate. The Argentine climate is predominantly temperate with extremes ranging from subtropical in the north to arid/sub-Antarctic in far south.

Enclaves and exclaves

There is one Argentine exclave: the island of Martín García (co-ordinates ). It is situated near the confluence of the Paraná and Uruguay rivers, a mere kilometre inside Uruguayan waters, about 3.5 km from the Uruguayan coastline, near the small city of Martín Chico (itself about halfway between Nueva Palmira and Colonia). An agreement reached by Argentina and Uruguay in 1973 reaffirmed Argentine jurisdiction over the island, ending a century-old dispute between the two countries. According to the terms of the agreement, Martín García is to be devoted exclusively to a natural preserve. Its area is about 2 km², and the population about 200 people.

Economy

Argentina benefits from rich natural resources, a highly literate population, an export-oriented agricultural sector, and a diversified industrial base. The country historically had a large middle class, compared to other Latin American countries, but this segment of the population was decimated by a succession of economic crises. Today, while a significant segment of the population is still financially well-off, they stay in sharp contrast with millions who live in poverty or on the brink of it. Since the late 1970s the country piled up public debt and was plagued by bouts of high inflation. In 1991, the government pegged the peso to the U. S. dollar and limited the growth in the monetary base. The government then embarked on a path of trade liberalisation, deregulation, and privatisation. Inflation dropped and GDP grew, but external economic shocks and failures of the system diluted its benefits, causing it to crumble in slow motion, from 1995 and up to the collapse in 2001. By 2002 Argentina had defaulted on its debt, its GDP had shrunk, unemployment was over 18%, the peso had devalued 75% after being floated, and inflation was hitting again. However, careful spending control and heavy taxes on now soaring exports gave the state the tools to regain resources and conduct monetary policy. In 2003, import substitution policies and soaring exports, coupled with a lower inflation and expansive economic measures, triggered a surge in the GDP, which was repeated in 2004, creating jobs and encouraging internal consumption. Capital flight decreased, and foreign investment slowly returned. The influx of foreign currency from exports created such a huge trade surplus that the Central Bank was forced to buy dollars from the market, which it continues to do at the time, to be accumulated as reserves. The situation in 2005 is much improved, but there are still large numbers of unemployed people that beg for some money or food, especially in the outskirts of Buenos Aires. Some of them are homeless, and there is at least one small non-profit humanitarian organisation which distributes free food to some of them most days of the week.

Demographics

Buenos Aires Buenos Aires Unlike most of its neighbouring countries, Argentina's population descends overwhelmingly from Europeans. The basic demographic stock (85% of the population) is made up of descendants of the Spanish colonists, augmented by descendants of later Italian and Spanish settlers. Around 56% of Argentinians, however, possess at least some indigenous Amerindian ancestry (as discovered by genetic research). Those who claimed their ancestry as Spanish — or Spanish and another ancestry, such as Spanish-Italian — were most likely to have some remnant Amerindian ancestry; a legacy of the almost complete absorption of colonial Argentina's mestizo majority by the post-colonial mass migratory influx of Europeans. The indigenous Amerindian — poorly estimated between 500,000 and 2 million — and identifiably mestizo populations are concentrated in the provinces of the north, northwest and south. As of 2001, 2.8% of Argentine households host a person that identifies as belonging to an indigenous group. Waves of immigrants from European countries arrived in the late 19th and early 20th centuries. The Patagonian Chubut Valley has a significant Welsh-descended population and retains many aspects of Welsh culture. Other important immigrant groups came from Germany (German colonies were settled in the provinces of Entre Ríos, Misiones, Formosa, Córdoba and the Patagonian region, as well as in Buenos Aires itself), France (mostly settled in Buenos Aires city and province), Scandinavia (especially Sweden) the United Kingdom and Ireland (Buenos Aires and the Patagonia) and Eastern European nations, such as Poland, Russia, Ukraine and the Balkans region (especially Croatia and Serbia) and others. The Jewish community in Argentina is comprised predominantly of Ashkenazi Jews of Northern and Eastern European origin, and [http://www.jewishvirtuallibrary.org/jsource/Judaism/jewpop.html numbers about 395,379], which is the largest in Latin America and fifth largest in the world. Syrian, Lebanese, and other Middle Eastern immigrants number about 500,000, mainly in urban areas. Small numbers of people from East Asia have settled Argentina, mainly in Buenos Aires. The first Asian-Argentines were of Japanese descent, but Koreans, Vietnamese, India and Chinese soon followed. There was a substantial immigration from other Latin American countries during the 1990s from Bolivia, Paraguay and Chile number about 2,000,000 and 4,000,000.

Culture

See also the articles on the cuisine, the music, and the football of Argentina. For a prevalent custom among Argentines, see mate. For the traditional Buenos Aires dance, see tango. Also see the list of people from Argentina.

Language

The only official language is Spanish, although some immigrants and indigenous communities have retained their original languages in specific points of the country. Argentina is the largest Spanish-speaking community that employs voseo (the use of the pronoun vos instead of tú, associated with some alternate verb conjugations). The most prevalent dialect is Rioplatense, with most speakers located in the basin of the River Plate.

Religion

River Plate Most of Argentina's population is at least nominally Roman Catholic (78%, though regular church attendance is much lower). Roman Catholicism is supported by the Argentine state, as stated in the Constitution. Evangelical churches gained a place in Argentina especially since the 1980s. The country also has the largest Jewish population in Latin America, about 300,000 strong, and is home to one of the largest Islamic mosques in Latin America. Members of the Church of Jesus Christ of Latter-day Saints (Mormons) number over 330,300, the seventh largest concentration in the world[http://www.lds.org.ar/noticias2005/noti_ene2005/info_noti_ene2005_05.htm]. Traditional Protestant communities are also present.

References

External links

Government
- [http://www.info.gov.ar Gobierno Electrónico] - Official governmental gateway
- [http://www.presidencia.gov.ar Presidencia] - Official presidential site (in Spanish)
- [http://www.senado.gov.ar Honorable Senado de la Nación] - Official senatorial site (in Spanish)
- [http://www.diputados.gov.ar Honorable Cámara de Diputados de la Nación] - Official lower house site (in Spanish) Directories
- [http://www.loc.gov/rr/international/hispanic/argentina/argentina.html Library of Congress Portals on the World - Argentina]
- [http://dmoz.org/Regional/South_America/Argentina Open Directory Project -Argentina] directory category
- [http://ar.todalanet.net Todalanet.net Argentina] - Search engine of Argentinean only web pages. News
- [http://www.telam.com.ar Official news agency]
- [http://www.tageblatt.com.ar Argentinisches Tageblatt] (in German)
- Buenos Aires Herald[http://www.buenosairesherald.com] (in English)
- Clarín[http://www.clarin.com], Argentina's most popular newspaper, published in Buenos Aires, distributed nationwide
- [http://www.diariodecuyo.com.ar Diario de Cuyo], from San Juan
- La Capital[http://www.lacapital.com.ar], from Rosario, Santa Fe Province
- [http://www.diariouno.net.ar Diario UNO], from Mendoza
- [http://www.eldiariodeparana.com.ar El Diario], from Paraná, Entre Ríos Province
- [http://www.infobae.com InfoBae], newspaper from Buenos Aires
- [http://www.lavozdelinterior.com.ar La Voz Del Interior], from Córdoba city
- [http://www.lagaceta.com.ar La Gaceta], from Tucumán
- La Nación[http://www.lanacion.com] ("The Nation"), from Buenos Aires, distributed nationwide
- [http://www.larazon.com.ar La Razón], Buenos Aires free evening newspaper (belongs to the Clarín group)
- [http://www.lanueva.com.ar La Nueva Provincia] ("The New Province"), from Bahía Blanca, Buenos Aires
- Página/12[http://www.pagina12.com.ar], from Buenos Aires (Clarín Group), distributed nationwide
- [http://www.lacapitalnet.com.ar La Capital], from Mar del Plata, Buenos Aires
- [http://www.lavozdelpueblo.com.ar La Voz del Pueblo], local newspaper from Tres Arroyos city Images
- [http://cometoargentina.tripod.com/ Mundo Argentina] - Has pictures
- [http://www.vester.com.ar/argentina/ Pictures of Argentina] - Pictures of Argentina. Provinces, regions, landscapes and people.
- [http://www.geographicguide.com/south-america.htm South America Pictures]
- [http://www.geographicguide.com/south-america-map.htm South America Map]
- [http://www.globe-images.com/south-america.htm South America Satellite Images]
- [http://www.fotos-de-argentina.com.ar/ Argentina Photos] Argentina Photos - Photographs of Argentina. Travel
- [http://www.turismo.gov.ar/ Secretaria de Turismo de la Nacion] Official site of the Tourism Department of the Argentine Government
- [http://www.argentinatravelnet.com/ Argentina Travel Net] Directory of travel websites in Argentina
- [http://www.roadjunky.com/argentina/guide_argentina.shtml Guide to Argentina] - Travel tips and a deep look at Argentine culture. (in English)
- [http://www.argentinacafe.com/ Argentina Cafe Travel Guide] - Travel highlights, costs, guidebook reviews, cheap flight tips, background articles, etc.
- [http://www.thowra.com/argentina.html Travelling in Argentina] - Find out about some of the main places to go. (in English)
- [http://www.VisitGayBA.com VisitGayBA.com] - A Gay Guide to Buenos Aires, Argentina. (in English) Other
- [http://www.josemariarosa.galeon.com/ Argentine History] - Prestigious Argentine historian José María Rosa (1906-1991).
- [http://www.argentina-information.com/ Argentina Information] - Facts and information on different aspects of life in Argentina.
- [http://www.coha.org Council on Hemispheric Affairs] Latin American information and analysis
- [http://expat-argentina.blogspot.com/ Expat Argentina] - Blog about expat life and issues in Argentina Argentina ko:아르헨티나 ms:Argentina ja:アルゼンチン simple:Argentina th:ประเทศอาร์เจนตินา fiu-vro:Argentina

Wladimir Köppen

Wladimir Peter Köppen (September 25, 1846 in Saint Petersburg, Russia — June 22, 1940 in Graz, Austria) was a German meteorologist, climatologist and botanist. He elaborated the Köppen climate classification system, which is still commonly used today to group climates into similar types (albeit with modifications). Although Köppen's parents were German, he himself was born in Russia and attended a school in Crimea. While being at the school, it was the first time that Köppen was attracted by the environment and especially by the relationship between plants and the climate they grow in. Later, he studied at the universities of Heidelberg and Leipzig in Germany where he graduated in 1870. His student dissertation dealt with the effects of temperature on plant growth. Between 1872 and 1873 Köppen was employed in the Russian meteorological service. In 1875, he moved back to Germany and became the chief of the new the Division of marine meteorology at the German naval observatory (Deutsche Seewarte) based in Hamburg. There he was responsible for establishing a weather forecasting service for the northwestern part of Germany and the adjacent sea areas. After four years of service, he was able to move on to his primary interest - the fundamental research - and left the meteorological office. Köppen began a systematic study of the climate and also experimented with balloons to obtain data from upper air. In 1884, he published the first version of his map of climatic zones in which the seasonal temperature ranges were plotted. This work led to the development of the Köppen climate classification system around 1900, which he kept improving for the rest of his life. The full version of his system appeared first in 1918 and, after several modifications, the final version was published in 1936. Apart from the description of various climate types, he was acquainted with paleoclimatology as well. In 1924 he and his son-in-law Alfred Wegener published a paper called Die Klimate der Geologischen Vorzeit (The climates of the geological past) giving a crucial support to the Milankovic theory on ice ages. Towards the end of his life, Köppen cooperated with the German climatologist Rudolf Geiger to produce a five-volume work, Handbuch der Klimatologie (Handbook of climatology). This was never completed, but several parts, three of them by Köppen, were published. After Köppen's death in 1940, Geiger continued to work on the modifications to the climate classification system.

References

- Allaby, Michael (2002). Encyclopedia of Weather and Climate. New York: Facts On File, Inc. ISBN 0-81-604071-0. Köppen, Wladimir Köppen, Wladimir Koppen, Wladimir Koppen, Wladimir Koppen, Wladimir ja:ウラジミール・ペーター・ケッペン

Köppen climate classification

The Köppen climate classification is one of the most widely used climate classification systems. It was developed by Wladimir Köppen, a German climatologist, around 1900 (with several further modifications by himself, notably in 1918 and 1936). It is based on the concept that native vegetation is the best expression of climate, thus climate zone boundaries have been selected with vegetation distribution in mind. It combines average annual and monthly temperatures and precipitation, and the seasonality of precipitation.

The scheme

Köppen climate classification scheme divides the climates into five main groups and several types and subtypes. Each particular climate type is represented by a 2 to 4 letter symbol:

GROUP A: Tropical/Megathermal climates

Tropical climates (see tropics) are characterized by constant high temperature (at sea level and low elevations) — all twelve months of the year have average temperatures of 18 °C (64.4 °F) or higher. They are subdivided as follows:
- Tropical rain forest climate (Af): All twelve months have average precipitation of at least 60 mm (2.36 inches). These climates, usually occurring within 5-10° latitude of the equator. In some eastern-coast areas, they may extend to as much as 25° away from the equator. This climate is dominated by the Doldrums Low Pressure System all year round, and thus has no real seasons. :Examples: Singapore,Belém, Brazil. :Some of the places that have this climate are indeed uniformly and monotonously wet throughout the year (e.g., the northwest Pacific coast of South and Central America, from Ecuador to Costa Rica, see for instance, Andagoya, Colombia), but in many cases the period of higher sun and longer days is distinctly wettest (as at Palembang, Indonesia) or the time of lower sun and shorter days may have more rain (as at Sitiawan, Malaysia). : A few places with this climate are found at the outer edge of the tropics, almost exclusively in the Southern Hemisphere; one example is Santos, Brazil.
Note. The term aseasonal refers to the lack in the tropical zone of large differences in day light hours and mean monthly (or daily) temperature throughout the year. There are annual cyclic changes in the tropics, not as predictable as thosse in the temperate zone, albeit unrelated to temperature but to water availability whether as rain, mist, soil, or ground water. Plant response (e. g., phenology), animal (feeding, migration, reproduction, et cetera), and human activities (plant sowing, harvesting, hunting, fishing, et cetera) are tuned to this seasonality. Indeed, in tropical South America and Central America, the rainy season (and the high water season) is called Invierno, even though it could occur in the northern hemisphere summer; likewise, the dry season (and low water season) is called Verano and can occur in the northern hemisphere winter.
- Tropical monsoon climate (Am): This type of climate, most common in southern Asia and West Africa, results from the monsoon winds which change direction according to the seasons. This climate has a driest month (which nearly always occurs at or soon after the "winter" solstice for that side of the equator) with rainfall less than 60 mm, but more than (100 − [total annual precipitation /25]): : Examples: Conakry, Guinea
Chittagong, Bangladesh. : There is also another scenario under which some places fit into this category; this is referred to as the trade-wind littoral climate because easterly winds bring enough precipitation during the "winter" months to prevent the climate from becoming a tropical wet-and-dry climate. Jakarta, Indonesia and Miami, Florida are included among these location.
- Tropical wet and dry or savanna climate (Aw): These climates have a pronounced dry season, with the driest month having precipitation less than 60 mm and also less than (100 − [total annual precipitation /25]): : Examples: Bangalore, India
Veracruz, Mexico
Townsville, Australia. : Most places that have this climate are found at the outer margins of the tropical zone, but occasionally an inner-tropical location (e.g., San Marcos, Antioquia, Colombia) also qualifies. Actually, the Caribbean coast, eastward from Urabá gulf on the Colombia–Panamá border to the Orinoco river delta, on the Atlantic ocean (ca. 4,000 km), have long dry periods (the extreme is the BSh climate (see below), characterised by very low, unreliable precipitation, present, for instance, in extensive areas in the Guajira, and Coro, western Venezuela, the northernmost peninsulas in South America, which receive <300 mm total annual precipitation, practically all in two or three months). This condition extends to the Lesser Antilles and Greater Antilles forming the Circumcaribbean dry belt. The length and severity of the dry season diminishes inland (southward); at the latitude of the Amazon river — which flows eastward, just south of the equatorial line — the climate is Af. East from the Andes, between the dry, arid Caribbean and the ever-wet Amazon are the Orinoco river' Llanos or Savannas, from where this climate takes its name. : Sometimes As is used in place of Aw if the dry season occurs during the time of higher sun and longer days. This is the case in parts of Hawaii (Honolulu), East Africa (Mombasa, Kenya) and Sri Lanka (Trincomalee), for instance. In most places that have tropical wet and dry climates, however, the dry season occurs during the time of lower sun and shorter days.

GROUP B: Dry (Arid and semiarid) climates

These climates are characterized by the fact that precipitation is less than potential evapotranspiration. The threshold is determined as follows:
- To find the precipitation threshold (in millimeters), multiply the average annual temperature in °C by 20, then add 280 if 70% or more of the total precipitation is in the high-sun half of the year (April through September in the Northern Hemisphere, or October through March in the Southern), or 140 if 30%-70% of the total precipitation is received during the applicable period, or 0 if less than 30% of the total precipitation is so received.
- If the annual precipitation is less than half the threshold for Group B, it is classified as BW (desert climate); if it is less than the threshold but more than half the threshold, it is classified as BS (steppe climate).
- A third letter can be included to indicate temperature. Originally, h signified low latitude climate (average annual temperature above 18 °C) while k signified middle latitude climate (average annual temperature below 18 °C), but the more common practice today (especially in the United States) is to use h to mean that the coldest month has an average temperature that is above 0 °C (32 °F), with k denoting that at least one month averages below 0 °C.
- Examples: Yuma, Arizona (BWh)
Turpan, China (BWk)
Cobar, Australia (BSh)
Medicine Hat, Alberta (BSk).
Some desert areas, situated along the west coasts of continents at tropical or near-tropical locations, are characterized by cooler temperatures than encountered elsewhere at comparable latitudes (due to the nearby presence of cold ocean currents) and frequent fog and low clouds, despite the fact that these places rank among the driest on earth in terms of actual precipitation received. This climate is sometimes labelled BWn and examples can be found at Lima, Peru and Walvis Bay, Namibia.
- On occasion, a fourth letter is added to indicate if either the winter or summer is "wetter" than the other half of the year. To qualify, the wettest month must have at least 60 mm of average precipitation if all twelve months are above 18 °C, or 30 mm (1.18 inches) if not; plus at least 70% of the total precipitation must be in the same half of the year as the wettest month — but the letter used indicates when the dry season occurs, not the "wet" one. This would result in Khartoum, Sudan being reckoned as BWhw, Niamey, Niger as BShw, El Arish, Egypt as BWhs, Asbi'ah, Libya as BShs, Umnugobi, Mongolia as BWkw, and Xining, China as BSkw (BWks and BSks do not exist if 0°C in the coldest month is recognized as the h/k boundary). If the standards for neither w nor s are met, no fourth letter is added.

GROUP C: Temperate/mesothermal climates

These climates have an average temperature above 10 °C (50 °F) in their warmest months, and a coldest month average between −3 °C and 18 °C. (Some climatologists, particularly in the United States, however, prefer to observe 0 °C rather than −3 °C in the coldest month as the boundary between this group and Group D; this is done to prevent certain headland locations in New England — principally Cape Cod — and such nearby islands as Nantucket and Martha's Vineyard, from fitting into the Maritime Temperate category noted below; this category is alternately known as the Marine West Coast climate, and eliminating the aforementioned locations indeed confines it exclusively to places found along the western margins of the continents, at least in the Northern Hemisphere).
- The second letter indicates the precipitation pattern — w indicates dry winters (driest winter month average precipitation less than one-tenth wettest summer month average precipitation; one variation also requires that the driest winter month have less than 30 mm average precipitation), s inidicates dry summers (driest summer month less than 30 mm average precipitation and less than one-third wettest winter month precipitation) and f means significant precipitation in all seasons (neither above mentioned set of conditions fulfilled).
- The third letter indicates the degree of summer heat — a indicates warmest month average temperature above 22 °C (71.6 °F), b indicates warmest month average temperature below 22 °C, with at least 4 months averaging above 10 °C, while c means 3 or fewer months with mean temperatures above 10 °C.
- The order of these two letters is sometimes reversed, especially by climatologists in the United States.
- Group C climates are subdivided as follows:
- Mediterranean climates (Csa, Csb): These climates usually occur on the western sides of continents between the latitudes of 30° and 45° (though on the west coast of North America, they occur in small patches as far north as 48°). These climates are in the polar front region in winter, and thus have moderate temperatures and changeable, rainy weather. Summers are hot and dry, due to the domination of the subtropical high pressure systems, except in the immediate coastal areas, where summers are milder due to the nearby presence of cold ocean currents.
Examples: Palermo, Sicily (Csa)
Gaziantep, Turkey (Csa)
San Francisco, California (Csb)
Victoria, Canada (Csb).
- Humid Subtropical climates (Cfa, Cwa): These climates usually occur in the interiors of continents, or on their east coasts, between the latitudes of 25° and 40°. Unlike the Mediterranean climates, the summers are humid due to unstable tropical air masses, or onshore Trade Winds. In eastern Asia, winters can be dry (and colder than other places at a corresponding latitude) because of the Siberian high pressure system, and summers very wet due to monsoonal influence.
Examples: Houston, Texas (Cfa — uniform precipitation distribution)
Brisbane, Australia (Cfa — summer wetter than winter)
Yalta, Ukraine (Cfa — summer drier than winter)
Luodian, China (Cwa).
- Maritime Temperate climates (Cfb, Cwb): Cfb climates usually occur on the western sides of continents between the latitudes of 45° and 55°; they are typically situated immediately poleward of the Mediterranean climates, although in Australia this climate is found immediately poleward of the Humid Subtropical climate, and at a somewhat lower latitude. In western Europe, this climate occur in coastal areas up to 62° latitude. These climates are dominated all year round by the polar front, leading to changeable, often overcast weather. Summers are cool due to cloud cover, but winters are milder than other climates in similar latitudes.
Examples: Limoges, France (uniform precipitation distribution)
Langebaanweg, South Africa (summer wetter than winter)
Prince Rupert, British Columbia (summer drier than winter).
Bergen, Norway (Cfb - uniform precipitation distribution)
Cfb climates are also encountered at high elevations in certain tropical areas, where the climate would be that of a tropical rain forest if not for the altitude. Bogotá, Colombia is perhaps the best example.
Cwb is found only at higher altitudes, without which the climate would be tropical wet and dry; examples include Addis Ababa, Ethiopia and Mexico City.
- Maritime Subarctic climates (Cfc): These climates occur poleward of the Maritime Temperate climates, and are confined either to narrow coastal strips on the western poleward margins of the continents, or, especially in the Northern Hemisphere, to islands off such coasts.
Examples: Punta Arenas, Chile (uniform precipitation distribution)
Monte Dinero, Argentina (summer wetter than winter)
Tórshavn, Faroe Islands (summer drier than winter)
Bodø, Norway (uniform precipitation distribution).

GROUP D: Continental/microthermal climate

These climates have an average temperature above 10 °C in their warmest months, and a coldest month average below −3 °C (or 0 °C in some versions, as noted previously). These usually occur in the interiors of continents, or on their east coasts, north of 40° North latitude. Group D climates do not exist at all in the Southern hemisphere due to the smaller land masses here.
- The second and third letters are used as for Group C climates, while a third letter of d indicates 3 or fewer months with mean temperatures above 10 °C and a coldest month temperature below −38 °C (−36.4 °F).
- Group D climates are subdivided as follows:
- Hot Summer Continental climates (Dfa, Dwa, Dsa): Dfa climates usually occur in the low 40s in latitude, and in eastern Asia Dwa climates extend further south due to the influence of the Siberian high pressure system, which also causes winters here to be dry, and summers can be very wet because of monsoon circulation.
Examples: Lowell, Massachusetts (Dfa — uniform precipitation distribution)
Peoria, Illinois (Dfa — summer wetter than winter)
Santaquin, Utah (Dfa — summer drier than winter)
Beijing, China (Dwa).
Dsa exists only at higher elevations adjacent to areas with Mediterranean climates, such as Cambridge, Idaho and Saqqez in Iranian Kurdistan.
- Warm Summer Continental or Hemiboreal climates (Dfb, Dwb, Dsb): Dfb and Dwb climates are immediately north of Hot Summer Continental climates, generally in the high 40s in latitude, and also in central and eastern Europe, between the Maritime Temperate and Continental Subarctic climates, where it extends up to high 50s and even lowest 60 degrees latitude.
Examples: Moncton, New Brunswick (Dfb — uniform precipitation distribution)
Minsk, Belarus (Dfb — summer wetter than winter)
Revelstoke, British Columbia (Dfb — summer drier than winter)
Rudnaya Pristan, Russia (Dwb).
Stockholm, Sweden (Dfb — summer wetter than winter)
Dsb arises from the same scenario as Dsa, but at even higher altitudes, and chiefly in North America since here the Mediterranean climates extend further poleward than in Eurasia; Mazama, Washington is one such location.
- Continental Subarctic or Boreal (taiga) climates (Dfc, Dwc, Dsc): Dfc and Dwc climates occur poleward of the other Group D climates, mostly in the 50s North latitude, although it might occur as far north as 69° latitude.
Examples: Sept-Îles, Quebec (Dfc — uniform precipitation distribution)
Anchorage, Alaska (Dfc — summer wetter than winter)
Mount Robson, British Columbia (Dfc — summer drier than winter)
Irkutsk, Russia (Dwc).
Kirkenes, Finnmark (Dfc - summer wetter than winter)
Dsc, like Dsa and Dsb, is confined exclusively to highland locations near areas that have Mediterranean climates, and is the rarest of the three as a still higher altitude is needed to produce this climate. Example: Galena Summit, Idaho.
- Continental Subarctic climates with extremely severe winters (Dfd, Dwd): These climates occur only in eastern Siberia. The names of some of the places that have this climate — most notably Verkhoyansk and Oymyakon — have become veritable synonyms for extreme, severe winter cold.

GROUP E: Polar climates

These climates are characterized by average temperatures below 10 °C in all twelve months of the year:
- Tundra climate (ET): Warmest month has an average temperature between 0 °C and 10 °C. These climates occur on the northern edges of the North American and Eurasian landmasses, and on nearby islands; they also exist along the outer fringes of Antarctica (especially the Palmer Peninsula) and on nearby islands.
Examples: Iqaluit, Nunavut
Provideniya, Russia
Deception Island, Antarctica.
Longyearbyen, Svalbard
ET is also found at high elevations outside the polar regions, above the timber line — as at Mount Washington, New Hampshire.
- Ice Cap climate (EF): All twelve months have average temperatures below 0 °C. This climate is dominant in Antarctica (e.g., Scott Base) and in inner Greenland (e.g., Eismitte or North Ice).
- Occasionally, a third, lower-case letter is added to ET climates if either the summer or winter is clearly drier than the other half of the year; thus Qikiqtaruk, or Herschel Island, off the coast of Canada's Yukon Territory, becomes ETw, with Pic du Midi de Bigorre in the French Pyrenees acquiring an ETs designation. If the precipitation is more or less evenly spread throughout the year, ETf may be used, such as for Hebron, Labrador. When the option to include this letter is exercised, the same standards that are used for Groups C and D apply, with the additional requirement that the wettest month must have an average of at least 30 mm precipitation (Group E climates can be as dry or even drier than Group B climates based on actual precipitation received, but their rate of evaporation is much lower). Seasonal precipitation letters are almost never attached to EF climates, mainly due to the difficulty in distinguishing between falling and blowing snow, as snow is the sole source of moisture in these climates.

Trewartha climate classification scheme

The Trewartha climate classification scheme is a modified version of the Köppen system. It attempts to redefine the broad climatic groups in such a way as to be closer to vegetational zoning.
- Group A: This the tropical climate group, defined the same as in Köppen's scheme (i.e., all 12 months average 18 °C or above). Climates with no more than two dry months (defined as having less than 60mm average precipitation, same as per Köppen) are classified Ar (instead of Köppen's Af), while others are classified Aw if the dry season is at the time of low sun/short days or As if the dry season is at the time of high sun/long days. There was no specific monsoon climate identifier in the original scheme, but Am was added later, with the same parameters as Köppen's (except that at least three months, rather than one, must have less than 60mm average precipitation).
- Group B: BW and BS mean the same as in the Köppen scheme, with the Köppen BWn climate sometimes being designated BM (the M standing for "marine"). However, a different formula is used to quantify the aridity threshold: 10 X (T − 10) + 3P, with T equalling the mean annual temperature in degrees Celsius and P denoting the percentage of total precipitation received in the six high-sun months (April through September in the Northern Hemisphere and October through March in the Southern). If the precipition for a given location is less than the above formula, its climate is said to be that of a desert (BW); if it is equal to or greater than the above formula but less than twice that amount, the climate is classified as steppe (BS); and if the precipitation is more than double the value of the formula the climate is not in Group B. Unlike in Köppen's scheme, no thermal subsets exist within this group in Trewartha's, unless the Universal Thermal Scale (see below) is used.
- Group C: In the Trewartha scheme this category encompasses subtropical climates only (8 or more months above 10 °C). Cs and Cw have the same meanings as they do in Köppen's scheme, but the subtropical climate with no distinct dry season is designated Cr instead of Köppen's Cf (and for Cs the average annual precipitation must be less than 890mm [35 inches] in addition to the driest summer month having less than 30mm precipitation and being less than one-third as wet as the wettest winter month).
- Group D: This group represents temperate climates (4 to 7 months above 10 °C). Maritime temperate climates (most of Köppen's Cfb and Cwb climates, though some of these would fit into Trewartha's Cr and Cw respectively) are denoted DO in the Trewartha classification (although some places near the east coasts of both North America and Asia actually qualify as DO climates in Trewartha's scheme when they fit into Cfa/Cwa rather than Cfb/Cwb in Köppen's), while continental climates are represented as DCa (Köppen Dfa, Dwa, Dsa) and DCb (Köppen Dfb, Dwb, Dsb). For the continental climates, sometimes the third letter (a or b) is omitted and DC is simply used instead, and occasionally a precipitational seasonality letter is added to both the maritime and continental climates (r, w, or s, as applicable). The dividing point between the maritime and continental climates is 0 °C in the coldest month, rather than the Köppen value of −3 °C (as noted in the section on the Köppen scheme, however, some climatologists — particularly in the United States — now observe 0 °C in the coldest month as the equatorward limit of the continental climates in that scheme as well).
- Group E: This represents subarctic climates, defined the same as in Köppen's scheme (1 to 3 months with average temperatures of 10 °C or above; Köppen Cfc, Dfc, Dwc, Dsc, Dfd, Dwd). In the original scheme, this group was not further divided; later, the designations EO and EC were created, with EO (maritime subarctic) signifying that the coldest month averages above −10 °C, while EC (continental subartctic or "boreal") means that at least one month has an average temperature of −10 °C or below. As in Group D, a third letter can be added to indicate seasonality of precipitation. There is no separate counterpart to the Köppen Dfd/Dwd climate in Trewartha's scheme.
- Group F: This is the polar climate group, split into FT (Köppen ET) and FI (Köppen EF).
- Group H: Highland climates, in which altitude plays a role in determining climate classification. Specifically, this would apply if correcting the average temperature of each month to a sea-level value using the formula of adding 5.6°C for each 1,000 met