Hazardous inversion

Hazardous surface temperature inversion

Pesticide applications during hazardous surface temperature inversions can lead to spray drift causing severe damage up to several kilometres off target. Current regulations prohibit spraying of agricultural chemicals when hazardous temperature inversions exist.

Key points

• Spray applied at dawn, dusk and during the night is likely to be affected by surface temperature inversions.
• During hazardous inversions, air movement is much less turbulent than during the day.
• Weak turbulence leads to the accumulation of drift close to the surface.
• Airborne droplets can remain concentrated in the inversion layer for long periods of time.
• The direction and distance airborne droplets will move within a hazardous inversion is unpredictable and will vary depending on the surrounding landscape.