Absorption of light in the atmosphere by collision pairs of oxygen (O2)2

Atmospheric absorption bands by collision complexes of oxygen have been measured in long path optical experiments. About 1.5×10−3 of the incoming solar energy is absorbed by the O4 bands in the near uv, visible and near infrared spectral regions. A larger fraction of this energy goes into the 2 km layer above the surface. The possible consequences of excited metastable (O2)2 molecules for atmospheric chemistry are discussed.