The assimilation of forward oblique ionosonde profiles into the electron density assimilative model (EDAM)

A strong understanding of the spatial and temporal variation of the Earth's ionosphere (a magneto-ionic, refractive medium 50-1000 km above the Earth's surface) is paramount for the effective operation of radio systems for communication. Ionospheric measurements can be assimilated into models, such as the Electron Density Assimilative Model (EDAM) to produce three-dimensional global nowcasts of the ionospheric electron density. Conventional measurement techniques are prohibitively expensive and difficult to implement in areas such as oceans and are therefore sparse over vast expanses of the Earth. Information about these under-observed regions can instead be found by assimilating data from forward oblique ionosondes (FOIs) into ionospheric models. Here we present preliminary results for the assimilation of FOIs into EDAM, demonstrating that the background electron density can be successfully modified using FOIs to capture the bottomside structure of the ionosphere.