SporadicEas an indicator of wind structure in the lower ionosphere and the influx of meteors

Standard measurements of sporadic E blanketing frequencies (ƒbEs, assumed to indicate peak ion densities) during November 1965 from three temperate latitude stations are examined in the light of current theory that predicts two important properties of this variety of sporadic E: (a) that major events consist predominantly of slowly-recombining monatomic ions, probably of meteoric origin, and (b) that these ions converge and accumulate in thin layers through combined effects of the geomagnetic field and the profile of horizontal winds. Two such levels of convergence seem to be indicated by daytime ƒbEs data. The hypothesis of a meteoric origin for the ions suggests that major events of ƒbEs might correlate with the increased meteoric mass arriving during large showers, as shown by radar meteor data. Some evidence of this correlation is shown during the November 1965 Leonid meteor shower.