Tropical savanna climate

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Worldwide zones of Tropical savanna climate (Aw/As). Koppen-Geiger Map Aw present.svg
Worldwide zones of Tropical savanna climate (Aw/As).

Tropical savanna climate or tropical wet and dry climate is a type of climate that corresponds to the Köppen climate classification categories Aw (for a dry winter) and As (for a dry summer). The driest month has less than 60 mm (2.4 in) of precipitation and also less than of precipitation. [1] :200–1

Contents

This latter fact is in direct contrast to a tropical monsoon climate, whose driest month sees less than 60 mm (2.4 in) of precipitation but has more than of precipitation. In essence, a tropical savanna climate tends to either see less rainfall than a tropical monsoon climate or have more pronounced dry season(s).

In tropical savanna climates, the dry season can become severe, and often drought conditions prevail during the course of the year. Tropical savanna climates often feature tree-studded grasslands, rather than thick jungle. It is this widespread occurrence of tall, coarse grass (called savanna) which has led to Aw and As climates often being referred to as tropical savanna. However, there is some doubt whether tropical grasslands are climatically induced. Additionally, pure savannas, without trees, are the exception rather than the rule.

Versions

There are generally four types of tropical savanna climates:

Distribution

Tropical savanna climates are most commonly found in Africa, Asia and South America. The climate is also prevalent in sections of Central America, northern Australia, the Pacific Islands, in sections of North America and some islands in the Caribbean. 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. Similarly, the Caribbean coast, eastward from the Gulf of Urabá on the ColombiaPanamá border to the Orinoco river delta, on the Atlantic Ocean (ca. 4,000 km (2,485 mi)), have long dry periods (the extreme is the BSh climate (see below), characterized 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 (11.8 in) 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 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, such as in Honolulu, Hawaii. [2] This may also be due to a rain shadow effect that cuts off summer precipitation in a tropical area. This is the case in East Africa (Mombasa, Kenya, Somalia), Sri Lanka (Trincomalee) and coastal regions of Northeastern Brazil (from Fortaleza through Natal to Maceió), for instance. The difference between 'summer' and 'winter' in such locations is usually so slight that a distinction between an As and Aw climate is a quibble. In most places that have tropical wet and dry climates, however, the dry season occurs during the time of lower sun and shorter days because of reduction of or lack of convection, which in turn is due to the meridional shifts of the Intertropical Convergence Zone during the entire course of the year.

Cities with a tropical savanna climate

Some examples of tropical savanna climates

Accra, Ghana
Climate chart (explanation)
J
F
M
A
M
J
J
A
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O
N
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15
 
 
31
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56
 
 
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64
 
 
29
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36
 
 
31
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23
 
 
31
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Average max. and min. temperatures in °C
Precipitation totals in mm
Source: BBC Weather [3]
Monte Cristi, Dominican Republic
Climate chart (explanation)
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F
M
A
M
J
J
A
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O
N
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74
 
 
29
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47
 
 
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40
 
 
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28
 
 
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68
 
 
33
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108
 
 
31
21
 
 
84
 
 
29
20
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: NOAA [4]
Brasília, Brazil
Climate chart (explanation)
J
F
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A
M
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241
 
 
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172
 
 
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238
 
 
27
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249
 
 
26
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Average max. and min. temperatures in °C
Precipitation totals in mm
Source: World Weather Information Service
Darwin, Australia
Climate chart (explanation)
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A
M
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466
 
 
32
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373
 
 
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335
 
 
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108
 
 
33
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25
 
 
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2.3
 
 
31
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1.2
 
 
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5.8
 
 
32
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18
 
 
33
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65
 
 
34
25
 
 
137
 
 
34
26
 
 
276
 
 
33
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Average max. and min. temperatures in °C
Precipitation totals in mm
Source: Australian Bureau of Meteorology
Mandalay, Myanmar
Climate chart (explanation)
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F
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A
M
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4
 
 
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2
 
 
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1
 
 
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40
 
 
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138
 
 
37
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99
 
 
34
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74
 
 
34
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136
 
 
32
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150
 
 
33
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125
 
 
32
24
 
 
38
 
 
30
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6
 
 
28
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Average max. and min. temperatures in °C
Precipitation totals in mm
Tegucigalpa, Honduras
Climate chart (explanation)
J
F
M
A
M
J
J
A
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O
N
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5.3
 
 
26
14
 
 
4.7
 
 
27
15
 
 
9.9
 
 
30
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43
 
 
30
17
 
 
144
 
 
30
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159
 
 
29
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82
 
 
28
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89
 
 
29
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177
 
 
29
18
 
 
109
 
 
27
18
 
 
40
 
 
26
16
 
 
9.9
 
 
25
15
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: WMO [5]

See also

Related Research Articles

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Climate is the long-term average of weather, typically averaged over a period of 30 years. More rigorously, it denotes the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, which includes the ocean and ice on Earth. The climate of a location is affected by its latitude, terrain, and altitude, as well as nearby water bodies and their currents.

Tropics Region of Earth surrounding the Equator

The tropics are the region of Earth surrounding the Equator. They are delimited in latitude by the Tropic of Cancer in the Northern Hemisphere at 23°26′11.6″ (or 23.43656°) N and the Tropic of Capricorn in the Southern Hemisphere at 23°26′11.6″ (or 23.43656°) S; these latitudes correspond to the axial tilt of the Earth. The tropics are also referred to as the tropical zone and the torrid zone. The tropics include all zones on Earth where the Sun contacts a point directly overhead at least once during the solar year. Thus the maximum latitudes of the tropics have the same value positive and negative. Likewise they approximate, due to the earth not being a perfect sphere, the "angle" of the Earth's axial tilt. The "angle" itself is not perfectly fixed due chiefly to the influence of the moon, but the limits of tropics are a geographic convention, being an averaged form, not least the variance is very small.

Subtropics Geographic and climate zone

The subtropics are geographic and climate zones located roughly bordered the tropics at latitude 23° 27' and the temperate zones, north and south of the Equator.

Tropical climate Climate in the tropical region

Tropical climate is one of the five major climate groups in the Köppen climate classification. Tropical climates are characterized by monthly average temperatures of 18 ℃ (64.4 ℉) or higher year-round and feature hot temperatures. Annual precipitation is often abundant in tropical climates, and shows a seasonal rhythm to varying degrees. There are normally only two seasons in tropical climates, a wet season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense.

Köppen climate classification Climate classification system

The Köppen climate classification is one of the most widely used climate classification systems. It was first published by the German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936. Later, the climatologist Rudolf Geiger introduced some changes to the classification system, which is thus sometimes called the Köppen–Geiger climate classification system.

Semi-arid climate Climate with precipitation below potential evapotranspiration

A semi-arid climate, semi-desert climate, or steppe climate is the climate of a region that receives precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-arid climates, depending on variables such as temperature, and they give rise to different biomes.

Climate of India Climatic conditions of India

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Humid continental climate Category in the Köppen climate classification system

A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot summers and cold winters. Precipitation is usually distributed throughout the year. The definition of this climate regarding temperature is as follows: the mean temperature of the coldest month must be below −3 °C (26.6 °F) and there must be at least four months whose mean temperatures are at or above 10 °C (50 °F). In addition, the location in question must not be semi-arid or arid. The Dfb, Dwb and Dsb subtypes are also known as hemiboreal.

Wet season

The wet season is the time of year when most of a region's average annual rainfall occurs. Generally, the season lasts at least a month. The term 'green season' is also sometimes used as a euphemism by tourist authorities. Areas with wet seasons are dispersed across portions of the tropics and subtropics.

Climate of the United States Varies due to changes in latitude, and a range of geographic features

The climate of the United States varies due to changes in latitude, and a range of geographic features, including mountains and deserts. Generally, on the mainland, the climate of the U.S. becomes warmer the further south one travels, and drier the further west, until one reaches the West Coast.

Climate of Venezuela

The Climate of Venezuela is characterized for being tropical and isothermal as a result of its geographical location near the Equator, but because of the topography and the dominant wind direction, several climatic types occur which can be the same as found in temperate latitudes, and even polar regions. Latitude exerts little influence on the Venezuelan climate, but the altitude changes it dramatically, particularly the temperature, reaching values very different according to The weather.

Humid subtropical climate

A humid subtropical climate is a zone of climate characterized by hot and humid summers, and cold to mild winters. These climates normally lie on the southeast side of all continents, generally between latitudes 25° and 40° and are located poleward from adjacent tropical climates. It is also known as warm temperate climate.

Tropical monsoon climate Climate subtype in the Köppen climate classification system

An area of tropical monsoon climate is a type of climate that corresponds to the Köppen climate classification category "Am". Tropical monsoon climates have monthly mean temperatures above 18 °C (64 °F) in every month of the year and a dry season. Tropical monsoon climates is the intermediate climate between the wet Af and the drier Aw.

Earth rainfall climatology

Earth rainfall climatology Is the study of rainfall, a sub-field of meteorology. Formally, a wider study includes water falling as ice crystals, i.e. hail, sleet, snow. The aim of rainfall climatology is to measure, understand and predict rain distribution across different regions of planet Earth, a factor of air pressure, humidity, topography, cloud type and raindrop size, via direct measurement and remote sensing data acquisition. Current technologies accurately predict rainfall 3–4 days in advance using numerical weather prediction. Geostationary orbiting satellites gather IR and visual wavelength data to measure realtime localised rainfall by estimating cloud albedo, water content, and the corresponding probability of rain. Geographic distribution of rain is largely governed by climate type, topography and habitat humidity. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation. On the leeward side of mountains, desert climates can exist due to the dry air caused by compressional heating. The movement of the monsoon trough, or intertropical convergence zone, brings rainy seasons to Savannah climes. The urban heat island effect leads to increased rainfall, both in amounts and intensity, downwind of cities. Warming may also cause changes in the precipitation pattern globally, including wetter conditions at high latitudes and in some wet tropical areas. Precipitation is a major component of the water cycle, and is responsible for depositing most of the fresh water on the planet. Approximately 505,000 cubic kilometres (121,000 cu mi) of water falls as precipitation each year; 398,000 cubic kilometres (95,000 cu mi) of it over the oceans. Given the Earth's surface area, that means the globally averaged annual precipitation is 990 millimetres (39 in). Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes.

The Climate of Cebu is a tropical wet and dry climate. There are two seasons in Cebu - the wet season and the dry season. Cebu has three different climates, based on the distribution of rainfall, with the most prevalent ones being Am and Af and a very minor area of Aw. Based on temperature, the warmest months of the year are March through October; the winter monsoon brings cooler air from November to February. May is the warmest month, and January, the coolest.

Seasonal tropical forest

Seasonal tropical forest, also known as moist deciduous, semi-evergreen seasonal, tropical mixed or monsoon forests, typically contain a range of tree species: only some of which drop some or all of their leaves during the dry season. This tropical forest is classified under the Walter system as (ii) tropical climate with high overall rainfall concentrated in the summer wet season and cooler “winter” dry season: representing a range of habitats influenced by monsoon (Am) or tropical wet savannah (Aw) climates. Drier forests in the Aw climate zone are typically deciduous and placed in the Tropical dry forest biome: with further transitional zones (ecotones) of savannah woodland then tropical and subtropical grasslands, savannas, and shrublands.

Hainan Island monsoon rain forests

The Hainan Island monsoon rain forests ecoregion covers mountainous interior of Hainan Island in China. The tropical forests receive over 1,000 mm/year of rain, heavily concentrated in the summer rainy season. The island has high levels of biodiversity, with over 4,200 plant species, 630 of which are endemic to the island. The region is under ecological pressure from deforestation for agriculture and timber extraction.

Southern Vietnam lowland dry forests

The Southern Vietnam lowland dry forests ecoregion covers the low, relatively arid coastal strip of southern Vietnam on the South China Sea. The region is in the rain shadow of the Southern Annamite Range, which blocks humid air from the west. Although approximately half of the ecoregion is forested to some degree, most has at some point been cleared for agriculture or degraded by extraction of hardwoods. There are few protected areas.

Miskito pine forests

The Miskito pine forests ecoregion covers lowland pine forests and savanna along much of the Mosquito Coast in northeastern Nicaragua and southeastern Honduras. Pines are adapted to grow in the poor soil, relative to the surrounding moist forest, and repeated burning have left one species – the Caribbean pine – dominant. Although the ecoregion receives high levels of rain, the hard soils, repeated burning, and exposure to hurricanes have left expanses of 'pine savanna' and seasonal wetlands. The area is thinly settled by humans and there is little crop agriculture.

Coastal Venezuelan mangroves

The Coastal Venezuelan mangroves ecoregion covers the salt-water mangrove forests along the Caribbean Sea and Atlantic Ocean coast of Venezuela, from Cocinetas Basin to the edge of the Caño Manamo River and the Orinoco Delta in the east. It is one of the largest mangrove ecoregions in South America, with an area of 5,698 km2, and stretching across over 400 km of Venezuelan coastline.

References

  1. McKnight, Tom L; Hess, Darrel (2000). "Climate Zones and Types" . Physical Geography: A Landscape Appreciation . Upper Saddle River, New Jersey: Prentice Hall. ISBN   978-0-13-020263-5.
  2. "Honolulu, Hawaii Köppen Climate Classification". Weatherbase.
  3. "Average Conditions Accra, Ghana". BBC Weather. May 2011. Archived from the original on 21 October 2006. Retrieved 9 September 2009.
  4. "Station Name: MONTE CRISTI ... Country: DOMINICAN REPUBLIC". NOAA .
  5. "Weather Information for Tegucigalpa, Country: HONDURAS". WMO .