Laboratory Investigations of the Primary Products of Ozone Photolysis

Abstract

The photochemistry of the O/O₂/O₃ system has been described by Wayne (this volume, p. 240) and so will not be discussed further here. Measurements of the atmospheric dayglow (Noxon, 1968) have shown that the (0, 0) bands of the ‘infrared atmospheric’ system at λ = 1.27μm are the strongest of all atmospheric emissions although they cannot be seen from the ground because of reabsorption in the lower atmosphere. O₂(¹Δ_g) is thus the metastable species present in the largest concentration in the upper atmosphere. The photolysis of ozone by ultraviolet rediation is the only atmospheric production mechanism which could produce sufficient quantities of O₂(¹Δ_g) to explain the dayglow measurements. It is thus important from the atmospheric, as well as the fundamental photochemical, point of view to know the primary products of ozone photolysis in the ultraviolet spectral region.