In winter, water vapours and pollutants comes to lie in the lowermost layer of atmosphere by –
**Core Concept**
The lowermost layer of the atmosphere is known as the troposphere, where temperature decreases with altitude. In winter, the temperature gradient between the Earth's surface and the troposphere becomes more pronounced, leading to the accumulation of cold air near the ground.
**Why the Correct Answer is Right**
The correct answer is due to the phenomenon of temperature inversions, which occur when a layer of cool air forms near the ground, trapping warm air above. In winter, the cold air is denser and sinks to the ground, while the warm air rises and is trapped above. This creates a temperature inversion, where the temperature increases with altitude. As a result, water vapors and pollutants accumulate in the lowermost layer of the atmosphere.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the phenomenon of temperature inversions in the lowermost layer of the atmosphere.
**Option B:** This option is incorrect because it is not relevant to the accumulation of water vapors and pollutants in the lowermost layer of the atmosphere.
**Option C:** This option is incorrect because it is not a recognized term in atmospheric science.
**Clinical Pearl / High-Yield Fact**
Temperature inversions can have significant effects on air quality and human health, particularly in urban areas where pollutants can become trapped.
**Correct Answer: D. Temperature inversion.**