He Dry weatherit is the one that presents an annual average precipitation less than evaporation and transpiration in the same period. Also, since the air is dry, there are few clouds and the sun is intense. LSummers 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 difference in temperatures between day and night. This type of climate is the result of the global air circulation pattern. According to this pattern, equatorial air rises into the atmosphere and is heated by intense sunlight. In the process it loses some of its water vapor.
Eventually this air goes back down hundreds of kilometers from the equator and gets warmer as it goes down. Thus, the air continues to lose what little water vapor remains within itself. In such a situation, with dry air moving from above, zones of arid and semi-arid climates are inevitably generated in the peripheries of the tropics.
Other factors collaborate in the generation of these areas, such as the mountains that block the humid winds from the sea and force the air to rise. TO as it rises, it cools and causes rain on its slopes; then not enough water vapor remains to form rain on the inland side. This reinforces the dryness in deserts and steppes.
Characteristics of the dry climate
The main characteristic 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 have been without rain for years.
The semi-arid or steppe regions, although they receive a little more rain than the deserts, receive a maximum of 50 cm per year on average.
This amount of rainwater is only enough to maintain short grasses and scattered shrubs or sagebrush, which is the dominant vegetation in this type of climate.
Arid and semi-arid regions together make up 26% of the Earth’s land surface, and deserts make up 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 rain, dry winds, and high temperatures.
Another characteristic of a dry climate is that evaporation is greater than precipitation. Consequently, soils lack moisture.
For example, arid regions in the Middle East average less than 20 cm of rainfall per year, but annual evaporation rates are more than 200 cm.
This extreme evaporation contributes to dry and thick soils on which plant life is scarce.
In dry climates there is a wide variation in temperatures, both seasonal and daily. As 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, dropping even below freezing.
Arid or desert (BW according to the Köppen scale)
Dry desert climates can be found in the deserts of Africa. This includes the deserts of the Sahara, Libya, Nubia, Danakil, Grand Bara, Namib, and Kalahari.
For its part, the Middle East has the Arabian Desert, the Syrian Desert and the Lut Desert. On the other hand, South Asia has the deserts of Dasht-e Kavir, Dasht-e Lut and the Thar desert.
In relation to the American continent, the Mojave desert, the Sonoran desert and the Chihuahuense can be mentioned. For its part, the Australian continent has the Simpson Desert and the Victoria Desert.
With regard 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.
Also, part of the Canary Islands (especially Fuerteventura and Lanzarote) have hot and dry climates in the desert.
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. It ranges from Ukraine in the west to Russia, Kazakhstan, China, Turkmenistan, Uzbekistan Altai, Kopet Dag and Tian Shan.
Similarly, this dry climate variety can be found in the inner parts 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 cactus ( Carnegiea gigantea )
The saguaro cactus is a cactus that occurs in dry, hot and rocky climates. Its skin is smooth and waxy and it has a kind of rib that runs up and down the length of the plant.
Its branches grow upright on the trunk and it can get 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.
Steppecursores or desert clouds ( Lechenaultia divaricata )
A stepper is a plant that is shed by its roots and driven by the wind. In hot, dry climates they quickly grow into a spiny flowering plant.
Then this plant breaks off its root and rolls through the desert. In their movement, the steppeckers disperse their seeds.
When rolling, these plants can be made as small as a soccer ball or as large as a car. They grow and spread very quickly because the hot, flat desert terrain 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 4000 meters above sea level and reaches 10 m in height. Its appearance is that of a large pineapple.
This plant usually blooms and bears fruit 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 once its natural environment.
Rattlesnake ( Crotalus cerastes )
There are 32 known species of rattlesnakes. They all look slightly different with different patterns on their skin that vary in color, but they all have a triangular shaped head and a rattle at the end of the tail.
On the other hand, this snake has the ability to camouflage and is carnivorous. Their diet is mainly made up 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 soil it crosses. This ability makes it easy 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 the night to sneak up on its prey, and takes advantage of its great sense of sight, smell and hearing to hunt it. 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, pointed face. It is omnivore and its good hearing, sense of smell and sight make it a good hunter.
In addition, these foxes are of migratory habits and move south when food is scarce.
Females mate between January and March. After 50 to 60 days, they give birth to 2 to 6 young 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.
In relation to 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 are larger than these. Female hawks are even more ferocious than 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 almost disappeared, decimated by hunting and by the disappearance of its habitat. On the other hand, until the middle of the 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. Today, this bison is recovering thanks to protection plans and the establishment of extensive reserves.
Types of dry weather
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 moisture to evaporate in the intense heat. These winds generally flow downward, so the area is rarely penetrated by air masses that produce rain, generating very dry heat.
Semi-arid or steppe
This climate is found above the equator at latitude 35º N to 55º N, and is characterized by grasslands. It is a semi-arid climate that is located 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 tall grass meadow.
In general, the steppe is a transitional belt that surrounds the desert and separates it from humid climates. This type of climate exists in the interior regions of the continents of North America and Eurasia.
Moist air masses 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.
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