Statistical Analysis of Co-existence of Ionospheric Irregularities and Alfvénic Structures in the Equatorial Ionosphere

Ionospheric irregularities are fluctuations or structures of plasma density that affect the propagation of radio signals. Post-sunset ionospheric irregularities of the equatorial ionosphere are one of the major threats to the propagation of GNSS signals. In this work, we study the co-existence of post-sunset equatorial ionospheric irregularities with Alfvénic structures in order to assess the possible role of Alfvén waves in the production of irregularities and possible connection between growth rate or retarding growth rate of irregularities in the conjugate points on two sides of equator. We use density, electric and magnetic field from the Swarm satellites at altitudes of ~500 km.