Estimates of the scattering cross section of equatorial electrojet irregularities over the 3‐ to 7‐MHz frequency band

E_sq echo intensities recorded by a dynasonde system operated at Huancayo, Peru, are used to estimate the scattering cross section of equatorial electrojet plasma irregularities in the 3 to 7 MHz frequency band. The scattering radar cross section of vertically propagating ∼20‐m scale electrojet irregularities is estimated as ∼3×10⁻⁷ m⁻¹ over a period exhibiting ƒ₀E values of 2.7 to 2.9 MHz. The cross‐section variation with Bragg wavenumber k is found to be characterized with a power law index of approximately −3 over the HF band.