Nonlinearly coupled dynamics of irregularities in the equatorial electrojet

• Nonlinear influence of Farley Buneman mode on the Gradient drift mode, is investigated.
• Electron collision frequency and density gradient scale length get modified.
• A new quasimode gets excited due to the competition between these modes.
• It seems to be important for modelling of Equatorial Electrojet current system.

Kinetic wave description is used to study the nonlinear influence of background Farley Buneman (FB) modes on the Gradient Drift (GD) modes in the equatorial electrojet ionosphere. The dominant nonlinearity is mediated through the electron flux term in the governing fluid equation which further invokes a turbulent current into the system. Electron dynamics reveals the modification in electron collision frequency and inhomogeneity scale length. It is seen that the propagation and growth rate of GD modes get modified by the background FB modes. Also, a new quasimode gets excited through the quadratic dispersion relation. Physical significance of coupled dynamics between the participating modes is also discussed.