Chapter 7: Problem 16

Differentiate between stability and instability relative to a parcel of air rising vertically in the atmosphere.

Short Answer

Expert verified

In a stable atmosphere, a lifted air parcel returns to its original position as it becomes denser due to cooling. In an unstable atmosphere, a lifted air parcel continues to rise as it remains less dense despite cooling, due to the surrounding environmental air being cooler. Therefore, the main difference between stability and instability in air parcels lies in how they behave when lifted — either rising continuously or returning back to the original level.

Step by step solution

Stable Atmosphere Description

In a stable atmosphere, when a parcel of air rises, it cools and becomes denser than the surrounding air. As a consequence, the parcel is pushed back to its original position. This happens because in a stable atmosphere, temperature decreases slowly with altitude. Therefore, when the air parcel rises and expands, its temperature drops below the temperature of the surrounding environment. The colder (and therefore denser) air parcel sinks back to its initial level or even below, establishing its stability.

Unstable Atmosphere Description

In an unstable atmosphere, if an air parcel rises, it continues to climb freeley. As the air parcel rises and cools, it is still warmer and less dense than the surrounding air. In an unstable atmosphere, the temperature decreases rapidly with altitude. Therefore, the lifted air parcel's temperature will remain higher than the surrounding environmental air even though it cools due to expansion. The parcel being warmer and less dense than its surroundings will continue to climb until it reaches a level where its temperature matches the environmental temperature, hence showing instability.

Comparison of Stability and Instability

In summary, the differentiation between stability and instability of an air parcel in the atmosphere depends on how the lifted air parcel’s temperature and density compare to the environmental air. In a stable atmosphere, a lifted air parcel returns to its original position because it becomes cooler and denser than the surrounding air. In contrast, in an unstable atmosphere, a lifted air parcel continues to rise as it is warmer and less dense compared to its environment.

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Geography Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Differentiate between stability and instability relative to a parcel of air rising vertically in the atmosphere.

Short Answer

Step by step solution

Stable Atmosphere Description

Unstable Atmosphere Description

Comparison of Stability and Instability

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Geography Textbooks

Energy Security

Water Cycle

Migration and Identity

Health And Human Rights

Challenges In The Human Environment

River Landscapes

Study anywhere. Anytime. Across all devices.