Session 12 - Thermosphere and Ionosphere : Irregular dynamics and structures as a response to Space Weather Events
Mirko Piersanti (University of L'Aquila), Massimo Materassi (CNR, Italy)
Friday 9/11, 09:00-10:30 & 11:15-12:45
The Thermosphere – Ionosphere system is a medium highly structured on many time and spatial scales. On the one hand, it shows rather stable and robust large patterns of convection and currents (such as Sudden Impulses current convection pattern); on the other hand, high and low latitudes show very irregular, highly time-variable small scale patterns (namely, plasma turbulence causing scintillation on trans-ionospheric L-band signals, plasma bubbles, large scale travelling ionospheric disturbance). Both the exact mechanism of response to external drivers, and the role played by the thermosphere (in terms of neutral wind, atmospheric waves and plasma drift) in generating Ionosphere irregularities is not completely understood yet.
In the last two decades, the interest in Ionospheric irregularities at different time and space scales has been growing fast, because of the considerable effects on the manmade technological infrastructure such as: geomagnetically induced currents, or the threats to performance of the satellite communication and navigation. Since those irregularities are due to the presence and variability of plasma structures in the ionosphere, understanding physical mechanisms that regulate the formation of the latter and their dynamics, as a result of magnetosphere-ionosphere-thermosphere coupling, is crucial to develop reliable prediction models and mitigation techniques, in order to be able to tackle the effect on technological systems.
This Session solicits and welcomes contributors to make the point on their research about how such multiscale patterns respond to the Sun activity and to the ionosphere-thermosphere interaction. Such a subject is very relevant from a technological point of view as both radio communications and industrial facilities may be vulnerable to plasma turbulence and ionospheric induced currents at ground, respectively.