Maximum upper atmospheric turbulence results in the mesosphere from convective and/or dynamic instabilities induced by gravity waves. For the first time, by comparing the vertical accelerations induced by wind shear and the buoyancy force, it is shown that the critical Richardson number can be estimated. This new approach, for the first time, makes it is possible to establish and estimate the temperature gradient impact on dynamic instability development.

This manuscript presents a novel and interesting hypothesis about the seeding of equatorial spread F irregularities by meteors. Based on radar experiments, the study postulates that the triggering of these irregularities occurs even under very stable ionospheric conditions. The article demonstrates significant work on the relationship between meteors and F region irregularities at equatorial latitudes. The novel mechanism can encourage the ionospheric community to test this hypothesis.

For the first time, the authors show that, by using the similarity theory, the same formula can be obtained for the eddy diffusion coefficient as the commonly used formula derived by J. Weinstock. Our results also explain the discrepancy between the large cooling rates calculated by the authors and the temperatures given by the MSIS-E-90 model.