Atmospheric Phenomena.

The aim of this research is to provide a better understanding of processes taking place in normal and disturbed atmospheres. The Meinel band system of N2, which is one of the strongest emissions in normal auroras, has been investigated in order to predict its intensity and altitude profile under auroral conditions. Accurate generalized valence bond calculations GVB have been carried out on the ground state of the nitrogen molecule for internuclear distances from 0.80 to 5.00A. For comparitive purposes, corresponding Hartree-Fock HF and valence bond calculations are also reported. The GVB orbitals were used to construct additional configurations for use in configuration interaction CI calculations. Detailed CI calculations have been carried out on all doublet electronic states of N2 which can be formed from the first six ionic dissociation limits. Research has also been initiated on the formation of various triatomic molecules as a result of the deposition of energy into the atmosphere. In particular the photochemistry and radiative properties of various NOx compounds is under investigation. Improbed virtual orbital IVO, HF and CI calculations have been carried out for the 16 excited states of H2O that can be formed by excitation from the two highest occupied orbitals of the ground state into a 3s or 3p Rydberg orbital.