Assertion (A): The amount of dust particles is less in subtropical and temperate areas than in equatorial area. Reason (R): The atmosphere is dry and windy in the subtropical and temperate areas.

The Assertion (A) is false because the concentration of dust particles is actually higher in subtropical and temperate regions compared to equatorial and polar regions [c1, t1]. This is primarily due to the presence of dry winds and arid conditions in these latitudes [c1]. The Reason (R) is true; subtropical and temperate areas, particularly those housing major hot deserts like the Sahara, are characterized by dry and windy conditions [c4, c5]. These dry winds facilitate the uplift and transport of fine soil and dust particles into the atmosphere [c2, t6]. In contrast, the equatorial region experiences high humidity and frequent rainfall, which leads to 'rain wash out' or wet deposition, effectively removing dust from the atmosphere [t2, t3]. Therefore, while the reason correctly describes the atmospheric conditions of these regions, the assertion incorrectly states the relative dust distribution.

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > Dust Particles > p. 65
2. [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 11: World Climate and Climate Change > Subtropical Steppe (BSh) and Subtropical Desert (BWh) Climates > p. 93
3. [3] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 14: Climate > Pressure and Planetary Winds > p. 140
4. [4] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 7: Arid or Desert Landforms > Landforms of Wind Deposition in Deserts > p. 72
5. [5] https://www.sciencedirect.com/topics/computer-science/atmospheric-condition