Question 91 from UPSC CSE 2025 - Geography

Question

Consider the following statements:
1. The amount of dust particles in the atmosphere is more in subtropical and temperate areas than in equatorial and polar regions.
2. Subtropical and temperate areas have less dry winds.
Which one of the following is correct in respect of the above statements?

IASCODEX · Accepted Answer

Correct Option: C. Statement I is correct but Statement II is not correct

Strategy: The key is to recall that wind and climate conditions dictate dust concentration. Subtropical and temperate areas, especially arid zones, have more dust due to frequent dry winds, not less. Statement I fits this, but Statement II contradicts basic climatic understanding, as these regions in fact have more dry winds. Thus, only Statement I is correct.

Key Info: Atmospheric dust particles mostly accumulate near the Earth's surface and are more prevalent in regions with arid or semi-arid climates. Subtropical zones (roughly 20°–35° latitude) encompass major deserts such as the Sahara, Arabian, and Australian deserts. These areas experience high solar heating, causing strong convection and frequent, persistent dry winds, which collect and suspend dust. Temperate grasslands can also have dust due to seasonal dryness and wind activity. Equatorial regions, characterized by high humidity, dense vegetation, and frequent rainfall, suppress dust suspension, while polar regions remain free of dust due to snow/ice cover and minimal atmospheric disturbances. Main sources of dry winds in subtropics include trade winds, westerlies, and specific regional winds like the Harmattan or Khamsin. Dust storms are most common in subtropics due to both aridity and wind. Statement II is factually incorrect, as subtropical and temperate areas are actually typified by more frequent and stronger dry winds than equatorial or polar zones.

IASCODEX · Answer

Option A: Both Statement I and Statement II are correct and Statement II explains Statement I

IASCODEX · Answer

Option B: Both Statement I and Statement II are correct but Statement II does not explain Statement I

IASCODEX · Answer

Option D: Statement I is not correct but Statement II is correct

Consider the following statements: The amount of dust particles in the atmosphere is more in subtropical and temperate areas than in equatorial and polar regions. Subtropical and temperate areas have less dry winds. Which one of the following is correct in respect of the above statements?

Consider the following statements:

The amount of dust particles in the atmosphere is more in subtropical and temperate areas than in equatorial and polar regions.

Subtropical and temperate areas have less dry winds.
Which one of the following is correct in respect of the above statements?