Decimetre and infrared radiation of the lower ionosphere during solar activity increase

  1. Semenov Institute of Chemical Physics RAS, Russia

   During geomagnetic disturbances a considerable change of electron
   temperature Te from media media temperature Ts, i.e.
   Te<<Ts occurs in E- and D-layers of the ionosphere. In the result
   a two-temperature weakly ionized recombinational plasma, the parameters of
   which are quite reliably determined on the basis of direct satellite
   measurements, is fixed. Since the frequency of electron collisions with
   media neutral particle is 1012- 1014 c-1, two local
   energy distributions of atom and molecule discrete states are formed. The
   first one (with Te temperature) corresponds to highly excited
   Rydberg states, higher than some energy E*. It is determined from
   the minimum condition of quenching rate constant due to transition to the
   lower state. The second one (with Ts media temperature) refers to
   low state. The bottleneck location is determined from the minimum
   condition of quenching rate constant due to transition to the lower state.
  

   The paper considers the main mechanisms of filling and quenching of
   Rydberg states in recombinational two-temperature plasma. The most
   important is the process of  l-mixing which cause formation of
   orbitally degenerated quasi-molecules  A**N2 and  A**O2.
   Filling of Rydberg states of quasi-molecules depend on the concentration
   of media, flux and temperature of electrons. A spectrum of decimeter range
   incoherent radiation is considered for the transition between split levels
   of these quasi-molecules. I was shown that it is inhomogeneous and
   contains three frequency ranges in which considerable decrease of
   radiation intensity occurs. The physical reason for the formation of these
   ranges is determined by quasi-molecule spectrum shift, which contain
   unexcited molecules N2 и O2. Formation of Rydberg
   quasi-molecules is accompanied by intensive super-background infrared
   radiation, the spectrum of which may be used to recover layer distribution
   of Rydberg particle filling in atmosphere D- and E- layers.