The northern and southern polar regions exhibit striking differences in ozone depletion and polar stratospheric cloud (PSC) formation. They are also significantly different in terms of energetic electron precipitation in the upper atmosphere. The suggestion has been made that PSC formation is stimulated by electron participation by creating bremsstrahlung X rays that penetrate to the stratosphere and ionize atmospheric constituents there which become nucleation centers for droplet formation. If correct, this would partially explain why ozone depletion and PSC formation occur almost exclusively in Antarctica: energetic electron precipitation is a common phenomenon there, but rarely occurs in the Arctic polar cap. An experiment to investigate this suggestion is to be conducted. A balloon payload with a strong, localized ionization source will be flown through the cold Arctic stratosphere; a photographic record would reveal whether the ionization had caused droplet formation to occur. A positive result from the experiment would have wide ranging implications. It would indicate that current models of stratospheric chemistry need to be revised and that additional experimental investigation of the stratosphere is needed.
