Analysis of Electromagnetic Wave Propagation in Variable Magnetized Plasma via Polynomial Chaos Expansion

A 3-D stochastic finite-difference time-domain algorithm is developed and applied to electromagnetic (EM) wave propagation in collisional magnetized plasma characterized by a variable electron density, collision frequency, and background magnetic field. The proposed stochastic model is based on the expansion of the random/variable time-domain electric and magnetic fields in terms of orthogonal polynomials in independent random variables representative of the variable ionospheric content. EM wave propagation in magnetized plasma having low variability (small deviations) and also high variability (large deviations) of the electron density, collision frequency, and background magnetic field is studied. The stochastic algorithm is validated against brute-force Monte Carlo results. The algorithm is considerably more computationally efficient than Monte Carlo. When applied to EM wave propagation in the ionosphere, the variability of the Earth's magnetic field and ionospheric parameters can be accounted for due to naturally varying space weather conditions and day-to-day variations, measurement errors, and so on. Although only electrons are considered here, positive and negative ions may be accommodated in a straightforward manner.