Which method can be used to check for a temperature inversion?

• A. Dust or smoke movement
• B. Water sampling
• C. Soil moisture measurement
• D. Sunlight intensity

Answer: (A)

Observing how dust or smoke behaves in the air tests for atmospheric stability near the ground. When a temperature inversion is present, the air right above the ground is cooler and very still, so dust or smoke tends to stay trapped in a shallow layer or move only slowly and horizontally rather than rising. If you see dust or smoke lifting and dispersing upward, the air isn’t inverted and the atmosphere is more mixed. This practical check helps you assess drift risk and spray timing.

Water sampling, soil moisture measurement, and sunlight intensity don’t provide a direct read on near-ground atmospheric stability, so they aren’t used to detect a temperature inversion.