MAGNETOSHEATH DENSITY-FLUCTUATIONS FROM A SIMULATION OF AURORAL KILOMETRIC RADIATION RADIO PROPAGATION

Using ray-tracing techniques in an inhomogeneous plasma, we calculate the direction and size of the scattered image of the low-frequency aur oral kilometric radiation (AKR) radio source seen through the magnetos heath and the shock by an observer in the 0200 to 0800 LT sector at ge ocentric distances of 50 to 250 R(E). The geometry of the limiting sur faces and the density distribution are those derived from in situ meas urements. A good fit to three sets of ISEE 3 observations is obtained at all frequencies assuming that the magnetosheath density inhomogenei ties are weak, their autocorrelation function Gaussian and their scatt ering power at twice the local f(p) is 4 x 10(-9) rad2 m-1. Variations of the model show to what extent observations of the AKR scattered im age could, in principle, yield information on the density jump r(s) ac ross the shock, its variation with X (GSE) and as a function of time.