Эти климатические явления вносят немалый вклад в pollution of the earth's atmosphere. It is one of the many incredible natural phenomena that the scientists quickly found a simple explanation.
These adverse climatic phenomena are dust storms. More details about them will be described in the following article.
Definition
Dusty or sandy, a storm is a phenomenontransfer of a huge amount of sand and dust by strong winds, which is accompanied by a sharp deterioration in visibility. As a rule, such phenomena are born on land.
These are arid regions of the planet, from where the airstreams carry powerful clouds of dust into the ocean. And, posing a considerable danger to humans mainly on land, they still greatly worsen the transparency of atmospheric air, making it difficult to observe the surface of the ocean from space.
Causes of dust storms
The thing is in terrible heat, due to which the soil dries up and then in the surface layer breaks up into microparticles, picked up by a strong wind.
But dust storms begin in certaincritical values of wind speeds, depending on the terrain and soil structure. For the most part, they begin at wind speeds within 10-12 m / s. And on loess soils, weak dust storms occur in summer even at speeds of 8 m / s, less often at 5 m / s.
Behavior
The duration of the storm varies from minutes to several days. Most often, time is counted in hours. For example, an 80-hour storm was recorded in the Aral Sea area.
After the disappearance of the reasons for the phenomenon describedthe raised dust from the surface of the earth remains in the air in a suspended state for several hours, possibly even a day. In these cases, its huge masses are carried by air streams to hundreds and even thousands of kilometers. Brought by the wind at great distances from the hearth, dust is called advective haze.
Colour
Dust storms have a very diverse coloring, which depends on the structure of the soils and their color. There are storms of the following colors:
- black (chernozem soils of the southern and southeastern regions of the European part of Russia, the Orenburg region and Bashkiria);
- yellow and brown (loam and sandy loam peculiar to the USA and Central Asia);
- red (red-colored, iron-oxide-colored soil of the desert areas of Afghanistan and Iran;
- white (salt marshes of some areas of Kalmykia, Turkmenistan and the Volga region).
Geography of storms
The emergence of dust storms occurs in completely different places on the planet. The main habitat is semi-desert and desert tropical and temperate climatic zones, with both terrestrial hemispheres.
Usually the term "dust storm" is used in itsoccurrence over loam or clay soil. When it occurs in sand deserts (for example, in the Sahara, Kyzylkum, Karakum, etc.), and in addition to the smallest particles, the wind carries millions of tons of air and particles larger (sand), the term "sandstorm" is already applied.
Often dust storms occur in Balkhash and in the Aral Sea (southern Kazakhstan), in the western part of Kazakhstan, on the Caspian coast, in Karakalpakstan and in Turkmenistan.
Where are dust storms in Russia? Most often they are observed in the Astrakhan and Volgograd regions, in Tyva, Kalmykia, as well as in the Altai and Trans-Baikal Territories.
The main sources of dusty mist near the Arabian Sea are the deserts of the Arabian Peninsula and the Sahara. The storms in Iran, Pakistan and India are less damaging to these places.
Chinese storms carry dust to the Pacific.
Ecological consequences of dust storms
The phenomena described are capable of moving hugedunes and carry large volumes of dust in such a way that the front can be represented as a dense and high wall of dust (up to 1.6 km.). Storms coming from the Sahara desert are known as Samum, Khamsin (Egypt and Israel) and Khabub (Sudan).
Следует отметить, что за последние 60 с лишним years, the number of dusty Saharan storms increased by about 10 times, which caused a significant decrease in the thickness of the surface layer of soil in Chad, Niger, Nigeria. For comparison, it can be noted that in Mauritania in the 60s of the last century there were only two dust storms, and today there are 80 storms per year.
Environmental scientists believe that irresponsibleattitude to the arid regions of the Earth, in particular, ignoring the system of crop rotation, steadily leads to an increase in desert areas and a change in the climatic state of planet Earth at the global level.
Methods of struggle
Пыльные бури, как и многие другие природные phenomena bring great harm. In order to reduce and even prevent their negative consequences, it is necessary to analyze the features of localities - relief, microclimate, the direction of the winds prevailing here, and take appropriate measures that will reduce the wind speed at the surface and increase the adhesion of soil particles.
To reduce wind speed, are heldcertain activities. Windproof backstage and forest belts systems are being created everywhere. A considerable effect for increasing the adhesion of soil particles is provided by shallow plowing, abandoned stubble, sowing of perennial grasses, strips of perennial grasses interspersed with sowing of annual crops.
Some of the most famous sand and dust storms.
For example, we offer you a list of the most well-known sand and dust storms:
- In 525 BC. e., according to the testimony of Herodotus, in the Sahara during the sandstorm killed 50 thousand troops of King Persia Kambiz.
- In 1928, in Ukraine, a terrible wind raised more than 15 million tons of black soil from an area of 1 million km², the dust of which was transferred to the Carpathian region, Romania and Poland, where it subsided.
- In 1983, a severe storm in the north of Victoria in Australia covered the city of Melbourne.
- In the summer of 2007, a severe storm occurred in Karachi and in the territories of the provinces of Baluchistan and Sindh, and torrential rains that followed it led to the death of about 200 people.
- In May 2008, 46 people died in Mongolia due to a sandstorm.
- In September 2015, the terrible "Sharav" (sandystorm) swept over a large area of the Middle East and North Africa. Israel, Egypt, Palestine, Lebanon, Jordan, Saudi Arabia and Syria were badly hit. There were also human casualties.
In conclusion, some of the extraterrestrial dust storms
Martian dust storms occur as follows.in a way. Due to the strong difference in temperature between the ice thickness and warm air on the edge of the southern polar cap of the planet Mars, strong winds arise, lifting huge clouds of reddish-brown dust. And here there are certain consequences. Scientists believe that the dust of Mars can play about the same role as terrestrial clouds. The atmosphere is heated by the absorption of dust by sunlight.
