GRAVITY-WAVE CHARACTERISTICS DERIVED FROM STRUCTURED ATOMIC OXYGEN PROFILE AND MULTIPLE E(S) LAYERS

We investigated the fine structures of lower thermospheric atomic oxyg en and electron density profiles obtained by a rocket experiment, assu ming that these structures are due to a quasi-monochromatic internal g ravity wave. The dissipation process of a gravity wave was inferred fr om the atomic oxygen profile. The height variation of the horizontal w ind amplitude is similar to that of the intrinsic horizontal phase spe ed below similar to 105 km, implying an evidence of saturation effects . At higher altitudes, dissipation due to molecular diffusion was sugg ested. The propagation direction of the wave was determined from both atomic oxygen and electron profiles based on the fact that the respons e of ionic species to gravity waves is different from that of neutral species depending on the propagation direction. The propagation direct ion inferred is interpreted as a consequence of selective transmission of gravity waves in lower atmosphere.