What would be the behavior of a smokestack plume under the strong lapse rate condition in which the decrease in temperature vs. altitude is much greater than normal?

Correct option is C

The correct answer is (c) Looping. Under a strong lapse rate condition, where the temperature decreases rapidly with altitude, the atmosphere becomes highly unstable. This instability causes the smokestack plume to rise and fall in a looping pattern due to significant vertical air movements.
Explanation:
· A strong lapse rate indicates that the temperature drops quickly as you go higher in altitude, leading to an unstable atmosphere.
· In an unstable atmosphere, rising air parcels continue to rise, and descending parcels continue to fall, creating vertical turbulence.
· When pollutants are released from a smokestack under these conditions, they disperse in a looping pattern, characterized by alternating upward and downward motions.
· This phenomenon allows pollutants to spread over a wider area but may still impact regions near the source.
Information Booster:
1. Looping Plume:
· Occurs in an unstable atmosphere with a strong lapse rate.
· The plume disperses in loops due to vertical air movements.
· Typical during hot sunny days with significant surface heating.
2. Types of Plume Behavior:
· Trapping (a): Occurs when pollutants are confined between two stable layers of the atmosphere.
· Fumigation (b): Occurs when pollutants are rapidly mixed downward toward the ground due to a stable layer aloft and unstable conditions below.
· Conning (d): Occurs under neutral conditions, where the plume rises and disperses uniformly, forming a cone shape.
Additional Knowledge:
· Strong Lapse Rate:
· Indicates rapid cooling with altitude (> 10°C/km).
· Leads to atmospheric instability and vertical mixing.
· Stable Atmosphere:
· Characterized by a weak lapse rate or temperature inversions, causing limited vertical mixing.
· Unstable Atmosphere:
· Encourages turbulent mixing and dispersal of pollutants.
· Applications:
· Understanding plume behavior helps in air quality management and predicting the spread of pollutants.
Key Points:
1. Looping occurs in unstable atmospheric conditions.
2. Trapping and fumigation occur in stable and mixed conditions, respectively.
3. Plume behavior is influenced by atmospheric stability and temperature gradients.
4. Effective pollution control requires understanding these plume patterns.