7 junio, 2024

Dry climate: what it is, characteristics, types, location, flora, fauna

What is dry weather?

He Dry weather It is the one that presents an average annual precipitation lower than the evaporation and transpiration in the same period. Also, since the air is dry, there are few clouds and the sun is intense. Lhe summers are hot to very hot and it rarely rains. Winter can be cold or warm and winter nights can be very cold.

Also, there is a big temperature difference between day and night. This type of climate is the result of the global air circulation pattern. In this pattern, equatorial air rises into the atmosphere and is warmed by strong sunlight. In the process it loses part of its water vapor.

Eventually this air comes back down hundreds of kilometers from the equator and gets hotter as it goes down. Thus, the air continues to lose the little water vapor that remains within itself. In such a situation, with dry air moving from above, zones of arid and semi-arid climates are inevitably generated on the peripheries of the tropics.

Characteristics of the dry climate

low precipitation

The main feature of a dry climate is low and infrequent rainfall. In arid or semi-desert areas, rainfall averages about 35 cm per year. Even some deserts go years without rain.

large expanses

Arid and semi-arid regions together make up 26% of the Earth’s land surface, and deserts comprise 12%.

Thus, dry climates are the most extensive; They occupy more than a quarter of the earth’s surface. In this climate, many plants and animals have adapted to live with minimal rainfall, dry winds, and high temperatures.

increased evaporation

Another characteristic of a dry climate is that evaporation is greater than precipitation. Consequently, the soils lack moisture.

For example, arid regions in the Middle East average less than 20 cm of rain per year, but annual evaporation rates are more than 200 cm.

This extreme evaporation contributes to dry, coarse soils on which plant life is sparse.

Extreme temperatures

In dry climates there is a wide variation in temperatures, both seasonal and daily. Since the sun’s rays are more direct, the temperature fluctuations between day and night are extreme.

In general, deserts have hot summers, cool nights, and mild winters. However, in cold deserts winters can be extremely cold, even falling below freezing point.

Location

Arid or desert (BW according to the Köppen scale)

Dry desert climates can be found in the deserts of Africa. This includes the Sahara, Libyan, Nubia, Danakil, Grand Bara, Namib and Kalahari deserts.

For its part, in the Middle East there are the deserts of Arabia, Syria and Lut. On the other hand, South Asia has the Dasht-e Kavir, Dasht-e Lut and Thar deserts.

In relation to the American continent, we can mention the Mojave, Sonora and Chihuahuan deserts. For its part, the Australian continent has the Simpson and Victoria deserts.

With respect to Europe, there is a small group of places that have a desert climate, such as the Cabo de Gata-Níjar Natural Park in Almería and a small area in the southwest of Murcia and Alicante, Spain.

Furthermore, part of the Canary Islands (especially Fuerteventura and Lanzarote) have hot and dry desert climates.

Semi-arid or steppe (BS according to the Köppen scale)

The largest steppe region on the planet, usually called the Great Steppe, is found in Eastern Europe and Central Asia. This goes from Ukraine in the west to Russia, Kazakhstan, China, Turkmenistan, Uzbekistan Altai, Kopet Dag and Tian Shan.

Similarly, this variety of dry climate can be found in the internal areas of Anatolia in Turkey, Central Anatolia and Eastern Anatolia. TOSome areas of southeastern Anatolia, a large area of ​​Armenia and the Pannonian Plain in eastern Europe (especially Hungary) maintain this type of climate.

Another large steppe (prairie) area is found in the central United States, western Canada, and northern Mexico.

In South America the cold steppe is found in Patagonia and in much of the highlands east of the southern Andes.

In addition, relatively small steppe areas can be found in the interior of the South Island of New Zealand.

flora and vegetation

prickly pear cactus (Opuntia ficus-indica)

The nopal cactus is made up of many circular pads that grow from a thick, round trunk. The pads are all covered with spines. In these pads, the cactus stores water for times of drought. The nopal can grow up to 2.10 m tall.

Small yellow flowers with red centers grow on some nopal cacti. They also produce edible red or purple fruits, called nopales.

saguaro cacti (giant carnegiea)

The saguaro cactus is a cactus that thrives in a dry, hot, and rocky climate. Its skin is smooth and waxy and it has a kind of rib that runs from top to bottom along the sole.

Its branches grow upright on the trunk and can become very tall. The saguaro is covered with 5 cm spines located on each of the vertical ribs.

When it rains, this cactus absorbs water and keeps it on its ribs. This special ability allows him to survive in the extremely hot and dry desert climate.

Steppicursors or desert clouds (Lechenaultia divaricata)

A steppicursor is a plant that detaches from its roots and is driven by the wind. In dry and hot climates they grow rapidly into a thorny flowering plant.

This plant then breaks off its root and rolls across the desert. In their movement, the steppicursors disperse their seeds.

By rolling, these plants can become as small as a football or as large as a car. They grow and spread very quickly because the hot, flat terrain of the desert makes it easy for them to travel.

the titanca (Puya raimondii)

It is a very rare and exceptional plant from the Andean steppe of Peru and Bolivia. It grows at 4,000 meters above sea level and reaches 10 m in height. Its appearance is that of a large pineapple.

This plant flowers and bears fruit usually when it is over a hundred years old, after which it dies. Today it has become a rare species that has disappeared from many areas that were previously its natural environment.

Fauna

Rattlesnake (Crotalus cerastes)

There are 32 known species of rattlesnakes. They all look a bit different with different patterns on their fur that vary in color, but they all have a triangular head and a rattle at the end of their tail.

On the other hand, this snake has the ability to camouflage and is carnivorous. Their diet consists mainly of small land animals, such as lizards and rodents.

thorny devil (moloch horridus)

The thorny devil is a type of lizard typical of dry climates the size of a human hand. It is covered in cone-shaped spines and has a spiny hump behind its head that it uses for protection.

Also, this lizard is usually yellow and brown, but these colors change depending on the type of ground it crosses. This ability makes it easier for them to hide in the desert climate.

Coyote (canis latrans)

The coyote is a member of the dog family. It has a brown coat mixed with hairs that can be brown, gray or rusty black.

This animal uses the darkness of night to sneak up on its prey, and uses its great sense of sight, smell and hearing to hunt it down. Coyotes mainly eat rabbits and other rodents.

corsac fox (vulpes corsac)

This fox is native to the Mongolian steppe. It is reddish-gray with long legs, large ears, and a short, pointy face. It is omnivorous and its good hearing, sense of smell and eyesight make it a good hunter.

In addition, these foxes have migratory habits and move south when food is scarce.

The females mate between January and March. After 50 to 60 days, they give birth to 2 to 6 pups at a time.

Steppe saker falcon (falco cherrug)

The saker falcon is a large, strong bird with large eyes and a short, hooked beak. On average, the birds are between 45 and 50 cm tall.

Regarding its natural habitat, it is found in Southeast Europe and Asia. However, they migrate to Kazakhstan and the Middle East in the winter.

This type of hawk hunts mammals such as rats, weasels, voles, stoats, squirrels, and birds. These birds pounce on their prey at a speed of around 300 kph and are very ferocious hunters.

Often they even attack prey that is larger than these. The female hawks are even more ferocious than the males.

bison (bison bison)

The bison or buffalo is perhaps the most typical herbivore of the steppe. Until the 19th century, there were two species of bison: the European bison and the North American bison.

Today, the European bison has all but disappeared, decimated by hunting and the disappearance of its habitat. On the other hand, until the mid-19th century huge herds of American bison used to run across the prairies.

Unfortunately, the fierce persecution carried out by planters and hunters have brought this species to the brink of extinction. Currently, this bison is recovering thanks to protection plans and the establishment of extensive reserves.

Types of dry climate

arid or desert

It is a desert completely devoid of vegetation. Low latitude, arid deserts are located between latitudes 15º N and 30º S.

This zone corresponds to the belt bordered by the Tropics of Cancer and Capricorn, to the north and south of the equator, respectively.

In this type of dry climate the winds are light. This allows the evaporation of moisture in the intense heat. These winds generally flow downward, so the area is rarely penetrated by rain-producing air masses, generating very dry heat.

semi-arid or steppe

This climate lies above the equator at latitude 35º N to 55º N, and is characterized by grasslands. It is a semi-arid climate that falls between the desert climate (BW) and more humid climates of groups A, C and D.

If it received less rain, the steppe would be classified as an arid desert. With more rain, it would be classified as a tallgrass prairie.

In general, the steppe is a transition belt that surrounds the desert and separates it from humid climates. This type of climate exists in the interior regions of the North American and Eurasian continents.

Moist air masses coming from the ocean are blocked by mountain ranges to the west and south. Consequently, the air that passes through is drier.

Likewise, these mountain ranges also trap air that comes from the poles in winter, making winters very cold and summers warm to hot.

References

Bailey, R. G. (2014). Ecoregions: The Ecosystem Geography of the Oceans and…

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