Discussion
The atmosphere is unstable when the environmental lapse rate is
Answer: B
Correct answer: Greater than the dry adiabatic lapse rate
The atmosphere is unstable when the environmental lapse rate exceeds the dry adiabatic rate of about \( 9.8 \) degrees per kilometre - the superadiabatic condition. A parcel displaced upward cools at the adiabatic rate, but the surrounding air cools faster with height, so the parcel finds itself warmer and less dense than its surroundings and keeps rising.
If the environmental rate is less than adiabatic the parcel becomes colder and denser than its surroundings and sinks back, which is stable. Equality gives neutral conditions, in which a displaced parcel neither rises nor sinks. Instability favours vigorous vertical mixing and rapid dilution of a plume.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development