Modeling HF scintillation from E-Region Plasma Instabilities

Trans-ionospheric signals are regularly disrupted by interactions with plasma irregularities, leading to both phase and amplitude scintillation. The length scale of these irregularities can span several orders of magnitude from centimeters to kilometers. Modeling ionospheric radio wave propagation therefore necessitates an approach that is inherently multi-scale and that can evaluate both refractive and diffractive effects. We demonstrate the use of FARR, a new finite-difference time-domain (FDTD) code that solves Maxwell’s equations, for evaluating HF scintillation. Because the FDTD method is a full vector solution of Maxwell’s equations, we can explore both diffractive and refractive effects. Here we present simulations of HF communication through irregularities generated by both the Farley-Buneman and Gradient Drift instabilities, which occur regularly in the E-region ionosphere. We also demonstrate the ability to generate realistic scintillation spectra using FARR.