Abstract. The finite-difference time-domain (FDTD) model of electromagnetic wave propagation in the
Earth–ionosphere cavity was developed under assumption of an axisymmetric system, solving the reduced Maxwell equations in a 2D
spherical coordinate system. The model was validated on different
conductivity profiles for the electric and magnetic field components for
various locations on Earth along the meridian. The characteristic electric
and magnetic altitudes, phase velocity, and attenuation rate were
calculated. We compared the results of numerical and analytical calculations
and found good agreement between them. The undertaken FDTD modeling enables
us to analyze the Schumann resonances and the propagation of individual
lightning discharges occurring at various distances from the receiver. The
developed model is particularly useful when analyzing ELF measurements.