Rocket measurement of electron density and atomic oxygen density modulated by atmospheric gravity waves Original Research Article

The results of a rocket experiment are presented and a parameterization method of gravity wave analysis using rocket data is established. The rocket experiment was conducted to obtain electron density, atomic oxygen density, and horizontal neutral wind profiles as a part of the WAVE2000 campaign. Wavelike structures around 90–100 km height were found in both electron and atomic oxygen density profiles, and we attributed these structures to an atmospheric gravity wave modulation. The motion of ionized particles in the lower E region is controlled by the motion of neutral species via collision under the effect of the geomagnetic field. Vertical and horizontal wavelengths, amplitude, frequency, and intrinsic phase speed of the wave are inferred from the electron density profile. The modulation process of the neutral layer by gravity waves differs from that of ionized layers, and the propagation direction of the gravity wave is inferred using the difference between those mechanisms. We could consistently explain the structures of the observed neutral wind, electron density, and atomic oxygen density profiles in terms of a quasi-monochromatic gravity wave modulation.