Construction of a model of equatorial scintillation intensity


  • Jules Aarons


By using a 5-year series of observations at 254 MHz taken at Huancayo, Peru, an analytical equation has been developed to yield scintillation excursions in decibels as a function of solar flux, magnetic index, local time, and day of the year; the equation, while characterizing the parameters given for the region surrounding the magnetic equator and for the Atlantic sector, has serious limitations in its application at other latitudes, other frequencies, and other longitudes in the equatorial region. Current available models of electron density and total electron content are inadequate to explain the differences between high levels of scintillation activity in years of high solar flux over the anomaly region relative to that of the magnetic equator. Newer models under development go further towards explaining levels of fading. Excursions levels of the order of 28 dB and greater have been observed in the anomaly region, while only 8–9 dB excursions have been noted at 1.6 GHz on the magnetic equator. The longitudinal characteristics indicate differences in activity over various regions of the earth particularly relative to solstice scintillation occurrence. Characteristics of the patches, such as intervals between patches and differing propagation paths when transmitting from multiple satellites, can be used to move information through the ionosphere even during nights of intense scintillations.