D-Region at Low Latitudes Using Partial Reflection Technique

Abstract

Partial reflection experimental set-up at Ahmedabad for the study of the lower ionosphere is described. Preliminary results are presented. The electron density is shown to vary almost linearly with the cosine of the solar zenith angle in the altitude region 75 to 90 km. The electron recombination coefficient is observed to be around 5 x 10^-6 cm^-3 sec^-1 at 80 km and 1 x 10^-7 near 90 km. Latitudinal variation of electron density reveals the existence of a geomagnetic control upto altitudes as low as 80 km.