Consider the following statements:Statement I: The amount of dust particles in the atmosphere is mor

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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?

Accepted Answer

Correct Answer: C - Statement I is correct but Statement II is not correctStep-by-step Solution:Statement I - More dust in subtropical and temperate areas vs. equatorial and polar regions: This is correct. Dust particles in the atmosphere (aerosols) are more abundant in subtropical and temperate regions for several reasons: Subtropical regions are dominated by hot deserts (Sahara, Arabian Desert, Thar) which are major sources of dust (aeolian transport); Temperate zones have seasonal dry conditions, agricultural activity (soil disturbance), industrial activity, and urban areas contributing to particulate matter; Equatorial regions are characterised by high rainfall (tropical rainforests) which wash out dust particles through wet deposition, keeping atmospheric dust relatively low; Polar regions are extremely cold, covered by ice/snow, with very little bare soil or industrial activity - dust concentrations are very low. ✓Statement II - Subtropical and temperate areas have less dry winds: This is incorrect. In fact, subtropical and temperate regions often experience strong dry winds. Examples include: Trade Winds in subtropical zones; Dry continental winds in temperate interiors (e.g., Siberian winds); Foehn winds (warm, dry descending winds on leeward side of mountains in temperate zones - Alps, Rocky Mountains); Sirocco, Harmattan, Khamsin - dry winds from subtropical deserts. Equatorial regions are characterised by calm (doldrums) and humid conditions. Polar regions have katabatic winds (cold but dry). The statement that subtropical and temperate areas have 'less dry winds' is incorrect - they have more dry winds than equatorial regions. ✗Why other options are incorrect:Option A: Incorrect. Statement II is wrong - subtropical/temperate areas have MORE dry winds, not less. And even if both were correct, dry winds are a cause of more dust (by transporting it), so the explanation relationship would be inverted.Option B: Incorrect. Statement II is factually incorrect.Option D: Incorrect. Statement I is correct.Key Concept: Atmospheric Dust (Aerosols): Sources: Deserts (aeolian erosion), volcanic activity, sea spray, biomass burning, industry, vehicle emissions. Distribution: Highest dust concentrations: Sub-Saharan Africa, Arabian Peninsula, South Asia (Thar Desert), Gobi Desert regions. The Saharan dust plume is the world's largest - it crosses the Atlantic to fertilise the Amazon. Tropical regions: High rainfall removes dust → cleaner atmosphere. Polar regions: Ice and snow cover, very little dust source. Dust affects: Climate (absorbs/scatters solar radiation), health (PM2.5, PM10), agriculture (dust deposition can add minerals), aviation (reduced visibility). India's dust storms in the Thar Desert region are seasonal and contribute to air quality deterioration in Northwest India.

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