Travelling Ionospheric Disturbances studied in the EU H2020 TechTIDE project

Abstract

Travelling Ionospheric Disturbances (TIDs) are propagating wavelike disturbances in the ionosphere electron density, which are signatures of atmospheric gravity waves that are active in the thermosphere. These waves are either generated in the thermosphere through intensive energy input from the solar wind or the solar terminator, or they are generated in the lower and middle atmosphere and propagate upwards into the thermosphere. Prominent sources of gravity wave which reach the thermosphere are earthquakes and tropical thunderstorms. Usually, gravity waves originating in the atmosphere below have smaller scales than those originating in the thermosphere. The corresponding TIDs are referred to as Medium Scale TIDs and Large Scale TIDs (LSTIDs). The EU Horizon 2020 project "Warning and Mitigation Technologies for Travelling Ionospheric Disturbances Effects - TechTIDE" implements a few different techniques for the detection of MS- and LSTIDs in the different layers of the ionosphere. They are based on different instruments and algorithms and deliver a comprehensive view on the TID activity in Europe and South Africa. The results of the different approaches will be presented for a case study for the September 2017 Space Weather event.