Momentum transfer collision frequency of O + ‐O

The interaction of the thermosphere and ionosphere is largely governed by collisions between ions and neutral particles. On Venus and the Earth, O + is a dominant ion, and atomic O dominates throughout much of the thermosphere; therefore an accurate O + ‐O cross section is an important prerequisite for understanding the dynamics of planetary upper atmospheres. The cross section and momentum, transfer collision frequency are calculated with a quantum mechanical code which includes resonance charge exchange, polarization, and charge‐quadrupole effects. Our results agree well with earlier calculations of Stubbe [1968] and Stallcop et al [1991].