Ozone (O3) is a secondary pollutant that is formed during a photochemical reaction when an oxygen atom is separated from a nitrogen dioxide molecule (NO2) under the influence of sunlight and combines with an oxygen molecule (O2). Ozone is an irritant gas, affecting living beings and materials.
Especially in the summer months, O3 is absorbed by plants. It then enters the leaves or needles through the stomata and damages the cell membranes. As the number of damaged cells increases, the photosynthetic capacity decreases and growth is slowed down.
If electricity is available in the forest, continuous measurements can be made with an ozone monitor. Compared to passive collectors (7), ozone monitors have the advantage that data can be measured every minute and automatically transferred to the LWF database. Ozone monitors absorb ambient air and measure their ozone concentration as a result of the absorption of UV radiation from a UV light, inside the monitor.