Short-period disturbances in the ionosphere observed at the time of typhoons in September 1982 by a network of HF Doppler receivers.

Abstract

Short-period disturbances of the ionosphere were observed by a network of HF Doppler receivers in central Japan at the time of typhoons 18 and 19 which crossed the Islands of Japan successively in September 1982.Both dynamic and static spectral analyses on sample records revealed that (1) these waves have the periods ranging between 1.4 and 9.7 min that correspond to infrasound at F-layer heights (and partly to gravity wave at E-layer heights), (2) the spectral content varies from hour to hour, from station to station for a given typhoon, and further one typhoon to the other, and (3) the spectral fine structure does not accord with existing theoretical prediction for thunderstorms. It is, therefore, plausible that the observed spectral peaks arose from the characteristics of the radiation sources in the typhoon air mass.Horizontal and vertical phase velocities, and corresponding wavelengths of the ionospheric waves were also measured using cross-correlation method. It is shown that (1) the horizontal phase velocities take similar values to those observed during the severe thunderstorms and tornadoes so far reported, with scatter range of the values being slightly larger than the latter two, and (2) the mean values of the upward vertical phase velocities are several to ten times larger than those of the horizontal ones.

Meteorological effects of ionospheric disturbances from vertical radio sounding data

“…The description of quasi-sinusoidal oscillations recorded during severe thunderstorms was given in Jones, 1971, Davies andJones, 1973;Prasad et al, 1975). Some authors (Shen, 1982;Okuzawa et al, 1986;Bishop et al, 2006;Perevalova and Polekh, 2009;Mao et al, 2010;Polyakova and Perevalova, 2011;Lin, 2012;Chernigovskaya et al, 2014a) revealed middle-and large-scale TIDs at the F2 layer heights during the development stage of tropical cyclones. There were also recorded other ionospheric effects of meteorological disturbances: infrasonic oscillations, electric fields, heating, optical emissions, scattering in the F layer (F-spread) (Inan et al, 1991;Taranenko et al, 1993;Huang and Kelly, 1996;Martinis and Manzano, 1999;Isaev et al, 2002;Šindelářová et al, 2009bŠindelářová et al, , Perminov et al, 2014.…”

Fifty Years of HF Doppler Observations

“…It is, therefore, plausible that the observed spectral peaks arose from the characteristics of the radiation sources in the typhoon air mass. (Okuzawa, Shibata, Ichinose, Takagi, Nagasawa, Nagano, et al, 1986) 6…”

Software-Defined-Radio Based HF Doppler Receiving System

“…The University of Electro-Communications (UEC) and the Radio Research Laboratory (RRL, now the National Institute of Information and Communications Technology) have also promoted HFD sounding in Japan. At UEC, the ionospheric disturbances in the lower atmospheres have been extensively examined, such as acoustic gravity waves (AGWs) (Shibata and Okuzawa 1983;Shibata 1986), earthquakes (Okuzawa et al 1983), and typhoons (Okuzawa 1986). At RRL, Kikuchi (1985) and Kikuchi et al (1986) focused on the storm-time variations in the electric eld in the ionosphere.…”