[Nethra K Putti]

DUSTSTORM - RESPONSIBLE FOR THE SPREAD OF DESERTS

When summer begins, many parts of the country begin to experience severe duststorms. these storms appear when a cold mass of unstable dry air blows speedily over sandy terrain. In summer such terrain heats up to a very high temperature & the air above it is warm & light. This air begins to rise & reaches a height of 10km, leaving below it a vast low perssure area. If a mass cold air happened to be stationed somewhere nearby,it will blow towards this low pressured area.

In India, DustStorms appear in the months just before the onset of the monsoon.Rajasthan, Punjab, U.P experience severe dust storms in April & May.When the temperature rises to about 45 degree Celsius the air is very dry upto a height of about 2km. When moist air enters the region just above this dry mass of air, electrical storms are generated, which invariably lead to rain. The raindrops evaporate the ground due to the heat & dryness of the atmosphere. What reaches the ground is a puff of cold air for each raindrop that has evaporated. At the same time strong surface wind is blowing, these little puffs of dust are picked up by the wind & blown into a fearsome duststorm.

Such storms usually appear in the afternoon.These dust clouds could rise up to a height of 4 km. The storm moves forward at a speed of 50km per hour.in the more severe storm , the dust stirred up may reduce visibility of zero.

During these storms large amounts of dust are transported to great distances in deserts. they could transport a 100 million tonnes of dust to thousands of kms. this supports a vegetative growth.

what is the best way to over come the destruction wrought by duststorms?