FAA Airline Transport Pilot (ATM)Meteorology and Weather ServicesEasy
A meteorologist observes that temperature increases with height in a shallow layer near the surface instead of decreasing as normal. What is this condition called, and what weather effect does it commonly produce?
- AAdiabatic lapse rate; increased turbulence
- BDry adiabatic lapse rate; rapid cloud dissipation
- CIsothermal layer; strong convective activity
- DTemperature inversion; trapping of fog, haze, and pollutants near the surface
Show answer & explanationAnswer & explanation
Correct answer: D. Temperature inversion; trapping of fog, haze, and pollutants near the surface
A temperature inversion occurs when temperature increases with altitude instead of the normal decrease. This creates a very stable layer that traps moisture, smoke, and pollutants near the ground, often producing fog or haze.
Why the other options are wrong
- A. Adiabatic lapse rate describes normal cooling with altitude, not an inversion.
- B. Dry adiabatic lapse rate refers to unsaturated air cooling, unrelated to inversions.
- C. An isothermal layer has constant temperature, not increasing temperature, and does not favor convection.
Temperature Inversion
A layer of the atmosphere in which temperature increases with height, creating strong atmospheric stability.
- Common on clear, calm nights (radiation inversion)
- Traps fog, smoke, and haze near the surface
- Associated with smooth air but poor visibility
Memory trick: Inversion = upside-down temperature, trapping the smog below