Sahara - desert, the greatest in the world.This area has become arid in the old days.However, there was a time when the Sahara was covered in savannas or forests.
According to some researchers, the climate was more humid area as compared with the present.Man during the Paleolithic fished and hunted, leaving far from his home.At that time he was not attached to the water source, like a modern oasis.However, when lack of fluid and heat became unbearable for him, he moved to another location.On the evidence of human activity tools, which are found throughout the arid territory.
modern Sahara desert has extremely dry, especially near the surface of the soil, air.This feature - a consequence of air Equatorial Current.Not the last role is played and the terrain on which lies the Sahara desert.
should be noted that in the world a place where there is no rain at all - a rarity.In some areas, this area is not sediment for several years and sometimes decades.Thus rain does not reach the surface of the soil - due to high soil temperature drops evaporate.
In some areas of the Sahara showers can go unexpectedly, causing severe floods, - area for a few minutes covered the water column with human growth.It is believed that in this arid region more people died from flooding than drought.
Sahara Desert, life is governed by the sun, it is considered to be the hottest area in the world.The high temperature of the surface of the soil contributes to the delimitation of air masses.In these areas takes the refraction of sunlight.As a result, there are mirages.On the horizon, in the midday heat, you may receive an oasis or a lake.In fact, they do not exist.Vision can arise in air saturated with dust, before sunrise.
Day, as we know, there is very hot.At night the temperature drops sharply, and becomes cold enough.Temperature fluctuations in the day may be up to thirty degrees.However, in practice, in the desert heat is transferred more easily than cold.
very severe impact on people have a long sand and dust storms.They are very similar to the fire and cover all around.Storms sweep across the plains, beating with eroded rocks stone dust.Wind force can reach, according to the individual investigators to 50 meters per second and more.
After such events the desert air is electrified.This spark can be drawn from virtually every subject.
Hot winds have a destructive force.They usually come from the center of the area and within a few hours can burn crop.Most of these winds begin to blow in the early summer.With the air flow not only moves dust and piled gravel.
In the Sahara there are brief tornadoes.These rotating air currents take the form of pipes.They arise due to the afternoon heat scorched soil.Tornadoes can be seen by the presence of dust in the air stream.However, observations show that such phenomena rarely cause damage.Sometimes they are breaking away from the surface, in the atmosphere are continuing.
Animals Sahara desert - mainly representatives of invertebrates.In total, there are about four thousand species.In the desert you can meet and adapted to life in the drylands of mammals - gazelle, antelope and sometimes predatory foxes.Numerous and reptiles - lizards, lizards, some species of snakes.
It should be noted the uniqueness of the Sahara.Even in arid areas preserved the integrity of the ecosystem.
