Book Description

HIS PAPER DISCUSSES SPACE-BORNE, NON-ELECTROMAGNETIC METHODS OF MODIFYING THE E- and F-regions of the terrestrial ionosphere. Of these, the most well-understood is the direct injection of chemical vapors into the ambient medium. The first injection of barium clouds into the upper atmosphere over two decades ago has led to evolution of understanding of complex electrodynamic processes acting in the ionosphere and spawned extensive studies of small-scale plasma instabilities. Modification to the ionosphere can last for up to hours from such injections. other vapors have also been released, including water vapor, SF 6 and more noxious gases, in successful efforts to alter the chemistry of the ionosphere. In another direction, injections of high amu gases from orbiting spacecraft have been made in attempts to understand the non-classical ionization processes involved in the critical ionization velocity (CIV) concept. The results seem to indicate that for CIV to act in space, large quantities of injected gas are required to achieve a minimum interaction volume density. However, in these and other experiments, it has been found that the potential CIV effects are supplemented by a variety of associated classical processes also acting for these same gases. For example, plasma disturbances are associated with neutral gas releases when charge exchange to ambient ions occurs. This leads to the formation of electrostatically polarized plasma clouds around the neutral gas-emitting space platform and these create large disturbances in the ionosphere.