Deriving main LAY parameters from Incoherent Scatter measurements and their comparisons with IRI-90

Abstract

Using high resolution electron density (Ne) profiles from Incoherent Scatter (I.S.) measurements at Arecibo, geometric parameters (transition height, scale height) of 4 LAY functions are determined. The median values of the above parameters are obtained for each hour during different seasons and compared with main LAY parameters obtained from IRI-90. It is observed that during all the seasons the transition height parameter of the F2 layer derived from observed profiles agrees well with the parameter obtained from IRI during daytime only, while for nighttime large departures are observed for all seasons. Large seasonal variability is also found in the principal scale parameter related to thickness of F2 layer. The difference between those in observed profiles compared to IRI varies from 38 km to 45 km.