Modelling and Observation of Sporadic E Layers and their dependence on upper atmospheric dynamics

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Knowledge on spatial and temporal variations of ionospheric irregularities can be used to increase the reliability of communication and navigation systems, but also for scientific investigations of coupling processes in the upper atmosphere. Within the proposed research project the formation of lower ionospheric sporadic E layers and their global distribution will be investigated in more detail based on satellite observations and model calculations. The main objective of this project is to analyse the global sporadic E distribution with respect to upper atmospheric dynamics, the Earth’s magnetic field and lower E region ionisation rates. GPS radio occultation data from the satellites CHAMP, GRACE and FORMOSAT- 3/COSMIC will be used to derive global distributions of sporadic E. These distributions will be correlated with global satellite based measurements of the thermospheric wind field and the Earth’s magnetic field. In addition a numerical model will be developed and applied to investigate the formation of sporadic E on a global scale and to interpret the observed global distributions of sporadic E. Ionisation rates in the lower ionosphere from meteor radar measurements are used as an important input parameter of the modelling. The developed model will be validated and applied within case studies to investigate open questions in the interpretation of the observed annual cycle of sporadic E occurrence, its spatial and temporal distribution and its correlation with the Earth’s magnetic field.