Interpretation of layered structure in mesospheric VHF echoes induced by an inertia gravity wave


  • Yoshikazu Muraoka,

  • Takuya Sugiyama,

  • Toru Sato,

  • Toshitaka Tsuda,

  • Shoichiro Fukao,

  • Susumu Kato


A remarkable layered structure of mesospheric VHF echo was observed on September 20, 1985, in the experiments with the middle and upper atmosphere (MU) radar at Shigaraki, Japan. The echoing layers were seen at the heights where the static stability in the atmosphere increases owing to the simultaneously observed inertia gravity wave motion. In this paper we show that the height profile of the observed echo power can be interpreted as due to the modulation of a mean gradient of potential refractive index by the gravity wave under the assumption of a height independent spectrum of turbulent irregularities. It is then shown that the enhancement of the observed echo agrees well with sharp gradients of electron density which are formed through the reactions between chemical species vertically transported by the wave.