Which statement is true about an unstable atmosphere?

Which statement is true about an unstable atmosphere?

• A. It encourages vertical motion
• B. It resists vertical motion
• C. It has uniform temperature
• D. It never changes

Answer: (A)

Unstable air promotes vertical motion because a lifted parcel stays buoyant and continues to rise. In an unstable environment, a parcel that moves upward remains warmer (less dense) than its surroundings, so buoyancy accelerates its ascent rather than opposing it. This creates sustained vertical motion and convection, leading to cloud development and sometimes storms. The idea that the atmosphere resists vertical motion describes stability, not instability. Uniform temperature isn’t a defining trait of instability, since instability depends on how temperature changes with height relative to a parcel’s adiabatic change. And the atmosphere certainly changes over time; it’s not fixed.

Unstable air promotes vertical motion because a lifted parcel stays buoyant and continues to rise. In an unstable environment, a parcel that moves upward remains warmer (less dense) than its surroundings, so buoyancy accelerates its ascent rather than opposing it. This creates sustained vertical motion and convection, leading to cloud development and sometimes storms. The idea that the atmosphere resists vertical motion describes stability, not instability. Uniform temperature isn’t a defining trait of instability, since instability depends on how temperature changes with height relative to a parcel’s adiabatic change. And the atmosphere certainly changes over time; it’s not fixed.