LASP Magnetosphere Seminars

Abstract

Plasma density irregularities in the equatorial E-region can produce rapid fluctuations in the phase and amplitude of radio signals, making ionospheric scintillation an important space-weather concern for communication and navigation systems. Understanding these effects requires connecting the plasma processes that generate irregularities across a wide range of scales with the full-wave propagation that produces scintillation at a receiver. This talk presents an end-to-end modeling approach that makes this connection. Hybrid particle-in-cell simulations capture the coupled gradient-drift and Farley–Buneman instabilities and provide the resulting density fields. These fields are then used by FARR, an open-source finite-difference time-domain code developed to model radio-wave propagation through magnetized ionospheric plasma. After reviewing the development and validation of FARR, I will describe how the simulated fields are transformed into receiver phase and amplitude spectra. Initial experiments indicate that, under the conditions studied, the modeled 12–24 MHz amplitude spectra are governed primarily by longer-wavelength gradient-drift structure and show limited sensitivity to meter-scale irregularities. This approach provides a physics-based bridge from instability growth to receiver observables relevant to assessing space-weather impacts on radio systems.