Previous Year Question
Consider the following statements:
Statement I: The amount of dust particles in the atmosphere is more in subtropical and temperate areas than in equatorial and polar regions.
Statement II: Subtropical and temperate areas have less dry winds.
Which one of the following is correct in respect of the above statements?
Both Statement I and Statement II are correct and Statement II explains Statement I
Both Statement I and Statement II are correct, but Statement II does not explain Statement I
Statement I is correct, but Statement II is not correct
Statement I is not correct, but Statement II is correct
Correct Answer: C
Detailed Solution
Statement I is correct. Subtropical regions contain extensive deserts such as the Sahara, Arabian and Kalahari deserts. Temperate regions also contain important dust sources, including the Gobi and the arid and semi-arid regions of Central Asia.
Desert and other arid surfaces possess sparse vegetation and loose, dry soil. Strong winds lift these particles from the surface and carry them into the atmosphere.
Equatorial regions experience abundant rainfall, high humidity and dense vegetation. Rain removes dust particles from the atmosphere, while vegetation binds the soil and limits the emission of dust.
A large part of the land in polar regions remains covered with snow and ice. The limited availability of exposed and dry soil results in comparatively lower atmospheric dust emissions.
Statement II is not correct. Dry winds are not less common in subtropical and several temperate arid regions; they occur substantially. These winds lift dust from deserts and dry soils and transport it over long distances.