On the generation of 3-m irregularities during equatorial spread F by low-frequency drift waves


  • J.D. Huba,

  • S.L. Ossakow


We consider the linear theory of low-frequency drift waves for parameters typical of the ionosphere during equatorial spread F. These waves are considered to be generated by density gradients associated with long-wavelength primary plasma fluid instabilities (e.g., collisional Rayleigh-Taylor). We include electron-ion, electron-neutral, and ion-ion collisions in our analysis. We find that a collisional drift wave can occur in the 3-meter regime but that it is heavily damped by ion viscosity. For density gradient scale lengths of ≳75 m it is required that n <2 × 10³ cm−3 for wave excitation to occur.