On the origin of ringing irregularities—A meteor hypothesis

Abstract

Isolated ionospheric irregularities produce oscillating (ringing) diffraction patterns on the ground. Typical physical properties such as density, size, etc. of these irregularities have been estimated using the characteristics of these diffraction patterns. These physical properties agree well with those of meteor trail ionisation. In addition it has been found that most of the ringing irregularities occur on meteor shower days. Further, investigations of diurnal and seasonal patterns of ringing irregularities and meteor showers suggest that the meteor showers are the most likely cause of ringing irregularities. Hence it is hypothesised that the ringing irregularities are caused by meteor showers. It is to be noted that the current observations of isolated ionospheric irregularities are near the equator (around 9^oN latitude) and they fill an observational gap in meteor showers which existed at equatorial latitudes. It has been observed that there is no marked difference in diurnal variation of meteor showers over the globe whereas there exists a strong latitudinal variation of the meteor showers.