A review of recent observations of equatorial scintillations and their relationship to current theories of F region irregularity generation

Our understanding of transionospheric radio wave propagation problems associated with irregularities in the nighttime equatorial F region has grown enormously in the past few years. This has been achieved by making coordinated phase and amplitude scintillations from a host of geostationary and orbiting satellites and multitechnique irregularity measurements. The variety of supporting measurements include radar backscatter, in situ irregularity observations by rockets and satellites, and airglow and ionosonde observations aboard aircraft. Because of the great volume of work in this field the scope of the present review is limited to a description of these recent coordinated observations and a discussion of the relevant theories of irregularity generation. An attempt is then made to explain some aspects of equatorial scintillations on the basis of these new theoretical developments.