Inversions occur when which condition is true?

Inversions occur when which condition is true?

• A. Warmer air above cooler air
• B. Warmer air near the surface
• C. Warmer air below cooler air
• D. Cooler air above

Answer: (A)

Inversions happen when temperature increases with height, so a layer of warmer air sits above cooler air. This arrangement creates a stable atmosphere that suppresses vertical mixing, trapping cooler air and any pollutants near the ground. The described condition—warmer air above cooler air—directly matches that inverted vertical temperature profile, making it the correct explanation. The other scenarios would either allow mixing or represent a normal or reversed temperature gradient, not an inversion.

Inversions happen when temperature increases with height, so a layer of warmer air sits above cooler air. This arrangement creates a stable atmosphere that suppresses vertical mixing, trapping cooler air and any pollutants near the ground. The described condition—warmer air above cooler air—directly matches that inverted vertical temperature profile, making it the correct explanation. The other scenarios would either allow mixing or represent a normal or reversed temperature gradient, not an inversion.