Atomic Collisions and the Lower Ionosphere at Midlatitudes

The Role of Excited Oxygen Molecules in the Formation of the Secondary Ozone Layer at 87 to 97 km

“…The spectrum of O 2 from 102 to 125 nm is very complex (see Figure 2) [18]. Lyman β line at 102.57nm is known to penetrate down to about 86 km level [19]. The ionization potential of oxygen molecules is 12.07eV, which is equal to the wavelength of 102.78nm.…”

“…[18] (1 cm -1 corresponds to a cross section of 3.72 x 10 -22 cm 2 ) Figure 3. Survey transmittance spectrum of the visible and near IR bands of O2 [24] Environment and Ecology Research 6(1): 74-85, 2018 77 UV at the Lyman α line (121.567nm) can penetrate down to 70km level [19]. Even though its O 2 absorption cross-section is small, about 1 x 10 -24 cm 2 [21], it is excitating O 2 molecules.…”

“…Even though its O 2 absorption cross-section is small, about 1 x 10 -24 cm 2 [21], it is excitating O 2 molecules. Its attenuating about ten-fold between 100 to 80 km is, of course, mainly due to ozone molecules [19]. Between the Lyβ and Lyα lines, there are eight bands (centred at 107, 109.…”

“…The location of the secondary ozone maximum can be set between altitudes of 87 to 97 km. An important detail is that this ozone layer is a part of the ionospheric D-region as well [9].…”