Gravity wave initiation of equatorial spread F: A case study

摘要: Jicamarca radar backscatter maps were made during four consecutive nights in March 1979. Two of these displayed single towering plumes extending to nearly 1000-km altitude. On a third night, discussed detail here, six generated clear association with sinusoidal oscillation the height bottomside F layer. The vertical amplitude was several hundred kilometers, and period about 100 minutes. either when layer at highest altitude or descending phase motion. Families curves are presented which correspond solution dispersion relation for gravity waves capable initiating observed oscillations via spatial resonance mechanism. We conclude that solutions thus derived reasonable present criterion how well matched wave velocity plasma drift have be produce given perturbation ionization density. This indicates although initiation by seems likely, interaction cannot yield large displacements without further amplification Rayleigh-Taylor instability. Finally, we show preferential generation can explained generalized instability operating on distorted ionosphere destabilizing effects gravity, zonal electric field, neutral wind included.