Electron deposition in water vapor, with atmospheric applications

We examine the consequences of electron impact on water vapor in terms of the microscopic details of excitation, dissociation, and ionization and combinations of these processes. Basic electron-impact cross section data are assembled in many forms and are incorporated into semi-analytic functions suitable for analysis with digital computers. Energy deposition in water vapor is discussed and the energy loss function is presented, along with the ‘electron volts per ion pair’ and the efficiencies of energy loss in various processes. We consider several applications of electron and water-vapor interactions in the atmospheric sciences, in particular, H2O comets, aurora and airglow, and lightning. In general we find that, except in the case of lightning, other processes are more likely sources of H*, O*, and OH* emissions.