D-region in disturbed conditions, including flares and energetic particles

A unified picture of the chemistry of the normal and the disturbed D-region is presented. The disturbed conditions included are solar flares, PCAs and solar eclipses. Several areas of identity in the observational results for flares and PCAs are discussed in relation to the six ion model of Mitra and Rowe. These include: The dominance of q(O2 (+)) over q(NO (+)) due to X-rays and energetic particles respectively; drastic decrease in the effective loss coefficient during both flares and PCAs; disappearance of water cluster ions down to 73 km during day and 78 km at night during PCAs; the reversion of negative ions to their basic forms (O (-) and O2 (-)) during PCAs. For solar eclipses, the effects are essentially a mirror image of those due to flares and PCAs.