Reference: McKee, David J., (editor), 1994: Tropospheric Ozone: Human Health and
Agricultural Impacts. Lewis Pub., Boca Raton. 333 pp.
Troposphere is the lowest 10 km (6 miles) of the atmosphere (approx.).
Ozone (O3) is a highly reactive gas composed of 3 atoms of oxygen.
Formation/Destruction of Tropospheric Ozone
Ozone is formed in the troposphere by various chemical reactions involving oxides of
nitrogen (NOx), reactive volatile organic compounds (VOC), and diatomic oxygen
(O2) in the presence of sunlight.
High atmospheric temperatures (>80ºF) or intense radiation at high altitudes are
required to form ozone.
Typical reactions:
NO2 + h (295 < λ < 430 µm) --> NO + O
O + O2 + M --> O3 + M
NO + O3 --> NO2 + O2 (rapid reaction)
Equilibrium condition:
[O3] = K [NO2] / [NO]