With reference to atmospheric stability and inversion layers, consider the following assertions: Assertion (A): Surface temperature inversions frequently develop on clear, calm winter nights over interior valleys. Reason (R): Rapid terrestrial radiation cools the ground surface, which in turn chills the air immediately above it while air aloft remains warmer. Which of the following is correct?

💡 Solution & Explanation

Assertion A is true because surface temperature inversions commonly form during long winter nights under clear skies. Reason R correctly explains that rapid outward terrestrial longwave radiation cools the ground surface efficiently, chilling the lowest layer of air through conduction while the air layer above remains at a higher temperature, inhibiting vertical mixing. Temperature inversions trap atmospheric pollutants and fog near the surface. The normal environmental lapse rate is inverted during these conditions.