  Fluorescence light is induced by extensive air showers while developing in
the Earth's atmosphere. The number of emitted fluorescence photons depends on
the conditions of the air and on the energy deposited by the shower particles
at every stage of the development. In a previous model calculation, the
pressure and temperature dependences of the fluorescence yield have been
studied on the basis of kinetic gas theory, assuming temperature-independent
molecular collision cross-sections. In this work we investigate the importance
of temperature-dependent collision cross-sections and of water vapour quenching
on the expected fluorescence yield. The calculations will be applied to
simulated air showers while using actual atmospheric profiles to estimate the
influence on the reconstructed energy of extensive air showers.
