Sunset - Lunar eclipse spectrum comparison
This annotates the telluric absorption features in the sunset and Lunar eclipse absorption spectra. It shows that the water and dimer (O_4) absorptions are much weaker in the eclipse (Pallé, E. et al. Nature volume 459, pages 814–816 (11 June 2009)) spectra since this samples predominantly the upper atmosphere where these species are rare. The dimer bands require a temporary pairing of oxygen molecules and so their relative abundance depends on the pressure.
An interesting discussion of the effect of ozone on sunrise and sunset sky colour is given by Frédéric Zagury and Mitsugu Fujii (New Astronomy, 2003, 8, p.549-556 ), available at :
Sunset - Lunar eclipse spectrum comparison
This annotates the telluric absorption features in the sunset and Lunar eclipse absorption spectra. It shows that the water and dimer (O_4) absorptions are much weaker in the eclipse (Pallé, E. et al. Nature volume 459, pages 814–816 (11 June 2009)) spectra since this samples predominantly the upper atmosphere where these species are rare. The dimer bands require a temporary pairing of oxygen molecules and so their relative abundance depends on the pressure.
An interesting discussion of the effect of ozone on sunrise and sunset sky colour is given by Frédéric Zagury and Mitsugu Fujii (New Astronomy, 2003, 8, p.549-556 ), available at :