Question

When the ambient lapse rate exceeds the adiabatic lapse rate, the ambient lapse rate is called the:

• A. Dry adiabatic lapse rate
• B. Super adiabatic lapse rate
• C. Saturated adiabatic lapse rate
• D. Sub-adiabatic lapse rate

Hint:

Super-adiabatic conditions indicate strong atmospheric instability and enhanced vertical mixing.

Answer 1

The Correct Option is B

Step 1: Understanding lapse rate.
Lapse rate is the rate at which atmospheric temperature decreases with an increase in altitude. Ambient lapse rate refers to the actual temperature gradient of the atmosphere.
Step 2: Comparing with adiabatic lapse rate.
The adiabatic lapse rate represents the rate of temperature change of a rising or falling air parcel without heat exchange. When the ambient lapse rate is greater than the adiabatic lapse rate, the atmosphere becomes highly unstable.
Step 3: Analyzing the options.
(A) Incorrect, this is a standard adiabatic reference rate.
(B) Correct, exceeding the adiabatic rate is termed super-adiabatic.
(C) Incorrect, this applies to saturated air conditions.
(D) Incorrect, sub-adiabatic means less than adiabatic.
Step 4: Conclusion.
When the ambient lapse rate exceeds the adiabatic lapse rate, it is known as the super adiabatic lapse rate.

Answer 2

This question is really about comparing two numbers, the actual (ambient) rate at which temperature falls with height and the reference (adiabatic) rate for a rising air parcel, so the reasoning should focus on what happens when the ambient value becomes larger than the adiabatic one.

1. Dry adiabatic lapse rate: This is the fixed reference rate itself, describing how a rising unsaturated air parcel cools; it is not a name used to describe the ambient atmosphere's own gradient.
2. Super adiabatic lapse rate: When the ambient lapse rate is numerically greater than the adiabatic lapse rate, a displaced air parcel stays warmer, and therefore less dense, than its surroundings at every height, so it keeps accelerating upward; this exaggerated, unstable condition is what is termed super-adiabatic.
3. Saturated adiabatic lapse rate: This term applies to a rising parcel that is saturated with moisture and releases latent heat as it condenses, which is a different physical scenario from comparing ambient conditions to the dry adiabatic reference.
4. Sub-adiabatic lapse rate: This describes the opposite situation, where the ambient rate is smaller than the adiabatic rate, producing a stable atmosphere, not the exceeding case described in the question.

Since the question specifically describes the ambient rate exceeding the adiabatic rate, and that condition is the definition of an exaggerated, unstable gradient, the matching term is the super-adiabatic lapse rate.

Therefore, the correct answer is Super adiabatic lapse rate.