Dust storms: causes, consequences. Where there are dust storms?
These climatic phenomena make a significant contribution topollution of the earth's atmosphere. It is one of many incredible natural phenomena, to which scientists quickly found a simple explanation.
These adverse climatic events are dust storms. More details about them will be discussed in the following article.
A dust or sandstorm is a phenomenon.the transfer of huge amounts of sand and dust by strong winds, which is accompanied by a sharp deterioration in visibility. As a rule, such phenomena originate on land.
These are arid regions of the planet, where airbornestreams carry powerful clouds of dust into the ocean. Moreover, representing a considerable danger to man mainly on land, they still greatly impair the transparency of atmospheric air, making it difficult to observe the ocean surface from space.
Causes of dust storms
It is all about the terrible heat, because of which the soil dries out strongly and then, in the surface layer, breaks up into microparticles caught by a strong wind.
But dust storms begin under certaincritical values of wind speeds, depending on the terrain and soil structure. Mostly they start at wind speeds ranging from 10-12 m / s. And on loess soils, weak dust storms occur in the summer even at speeds of 8 m / s, less often at 5 m / s.
The duration of storms varies from minutes to several days. Most often, time is calculated in hours. For example, an 80-hour storm was recorded in the Aral Sea region.
After the disappearance of the causes of the described phenomenonRaised dust from the earth’s surface remains suspended in the air for several hours, possibly even days. In these cases, its huge masses are carried by air currents hundreds and even thousands of kilometers. Blown by the wind at long distances from the center of dust is called advective haze.
Dust storms have the most varied color, which depends on the structure of the soil and its color. There are storms in the following colors:
- black (chernozem soils of the southern and south-eastern regions of the European part of Russia, Orenburg region and Bashkiria);
- yellow and brown (typical of the USA and Central Asia - loams and sandy loams);
- red (red, iron-colored soils 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 whenoccur over loamy or clay soil. When it arises in sandy deserts (for example, in the Sahara, Kyzylkum, Karakum and others), and besides the smallest particles, the wind carries millions of tons and larger particles through the air (sand), the term "sand storm" is already used.
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 the dust storms in Russia? Most often they are observed in the Astrakhan and Volgograd regions, in Tyva, Kalmykia, and also 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).
It should be noted that in the last 60 or soyears, 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 the planet Earth at the global level.
Methods of struggle
Dust storms, like many other naturalphenomena 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 significant 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 crops 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 Cambyses.
- 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 have been hit hard. 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 temperature difference between the ice thickness and warm air, strong winds arise on the edge of the southern polar cap of the planet Mars, 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 earthly clouds. The atmosphere is heated by the absorption of dust by sunlight.