Dust storms: causes, consequences. Where there are dust storms?

These climatic phenomena make a significant contribution to the 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 phenomenon of carrying 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 air flows carry powerful clouds of dust into the ocean. And, posing a considerable danger to humans mainly on land, they still greatly impair 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 out and then in the surface layer breaks up into microparticles, picked up by a strong wind.

But dust storms begin at certain critical values of wind speeds, depending on the terrain and soil structure. For the most part, they start 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 causes of the phenomenon described, the 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 or even thousands of kilometers. Brought by the wind for long distances from the hearth, dust is called advective haze. Tropical air masses are transferred to this darkness in the southern part of Russia and all of Europe from Africa (its northern regions) and the Middle East. And Western currents often carry such dust from China (center and north) to the Pacific coast, and so on.

Colour

Dust storms have a variety of colors, depending 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 soils of desert areas of Afghanistan and Iran;
• White (solonchak of some areas of Kalmykia, Turkmenistan and the Volga region).

Geography of storms

The occurrence of dust storms occurs in completely different places on the planet. The main area are semi-deserts and deserts of tropical and temperate climatic zones, both hemispheres.

Usually the term "dust storm" is used when it occurs over loamy 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 larger particles (sand), the term "sandstorm" is already applied.

Often dust storms occur in Pribalkhash and in the Aral Sea region (south of Kazakhstan), in the western part of Kazakhstan, on the Caspian coast, in Karakalpakstan and in Turkmenistan.

Where there 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 Transbaikalian regions. During periods of prolonged drought storms can develop (not every year) in the forest-steppe and steppe zones of Chita, Buryatia, Tuva, Novosibirsk, Orenburg, Samara, Voronezh, Rostov regions, Krasnodar, Stavropol territories, Crimea, etc.

The main sources of dusty haze near the Arabian Sea are the deserts of the Arabian Peninsula and the Sahara. Less damage in these places is brought by the storms of Iran, Pakistan and India.

In the Pacific, dust is endured by Chinese storms.

Environmental effects of dust storms

The phenomena described can move huge dunes and carry large volumes of dust in such a way that the front can be represented as a dense and high dust wall (up to 1.6 km). The storms coming from the Sahara desert are known as "Samum", "Khamsin" (Egypt and Israel) and "Khabub" (Sudan). Most of the Sahara storms occur in the basin of Baudela and at the junction of the borders of Mali, Mauritania and Algeria.

It should be noted that over the past 60-odd years, the amount of dusty Sahara storms has increased by about 10 times, which caused a significant reduction in the thickness of the surface layer of soil in Chad, Niger and Nigeria. For comparison, it can be noted that in Mauritania in the 60 years of the last century there were only two dust storms, and today there are 80 storms per year.

Environmental scientists believe that irresponsible treatment of the arid regions of the Earth, in particular, ignoring the crop rotation system, is steadily leading to an increase in desert areas and a change in the climatic condition of the planet Earth at the global level.

Methods of struggle

Dust storms, like many other natural phenomena, bring enormous harm. In order to reduce and even prevent their negative consequences, it is necessary to analyze the peculiarities of the terrain - the terrain, the microclimate, the direction of the winds prevailing here, and carry out appropriate measures that will help reduce the wind speed at the earth's surface and increase the cohesion of soil particles.

To reduce the speed of the wind, certain activities are carried out. Wind deflection wings and forest belts are created everywhere. A considerable effect for increasing the cohesion of soil particles is provided by unregulated plowing, abandoned stubble, sowing of perennial grasses, belts of perennial grasses alternating with sowings of annual crops.

Some of the most famous sand and dust storms

For example, we offer you a list of the most famous sand and dust storms:

• In the year 525 BC. E., according to Herodotus, in the Sahara during the sandstorm killed 50 thousandth army of the king of Persia Cambyses.
• In 1928 in Ukraine, a terrible wind raised more than 15 million tons of chernozem from an area of 1 million km², the dust of which was transferred to the Carpathian region, Romania and Poland, where it settled.
• In 1983, the strongest storm in the north of Victoria in Australia covered the city of Melbourne.
• In the summer of 2007, in Karachi and in the provinces of Balochistan and Sind, there was a severe storm, and the torrential rains that followed her led to the death of about 200 people.
• In May 2008, 46 people were killed in Mongolia because of the sandstorm.
• In September 2015, a terrible "sharov" (sandstorm) swept through the greater areas of the Middle East and North Africa. Israel, Egypt, Palestine, Lebanon, Jordan, Saudi Arabia and Syria suffered greatly. There were also human victims.

In conclusion, a little about extraterrestrial dust storms

Martian dust storms occur as follows. Due to the strong temperature difference between the ice thickness and warm air, strong winds arise on the outskirts of the southern polar cap of the planet Mars, raising huge clouds of dust of red-brown color. And here there are certain consequences. Scientists believe that the dust of Mars can play about the same role as the terrestrial clouds. The atmosphere is heated due to the absorption of sunlight by the dust.