Chair: M. Schmidt (Germany)
Space weather is an independent, very up-to-date and interdisciplinary field of research. It describes physical processes in space mainly caused by the Sun’s radiation of energy, but also induced by the radiation of energy from other cosmic sources. The manifestations of space weather are multiple, e.g.
- the variations of the Earth magnetic field
- the polar lights in the northern and southern hemisphere
- the variations of the upper atmosphere with the compartments ionosphere and thermosphere (due to coupling processes)
- the solar wind, i.e. the permanent emission of electrons and photons
- the interplanetary magnetic field, and
- the electric currents.
The most extreme known space weather event happened at September 1, 1859 – the so-called Carrington storm. Prominent recent events are the Halloween storm at October 28 – 30, 2003 or the Bastille Day Event at July 14, 2000 or the St. Patrick’s storm at March 17, 2015. The strength of these events, their impacts on modern society and the possibility of much stronger (i.e. more extreme) future events causing catastrophic effects have brought several countries such as US, UK, Japan, Canada and China to recognize the necessity
- of studying these impacts scientifically,
- of developing protection strategies and procedures and
- to establish space weather data centers and space weather services.
Several space-geodetic observation techniques provide valuable information about the state of the ionosphere. Thermospheric drag is the most important force acting on Low-Earth Orbiting satellites and objects in the re-entry stage. Thermospheric drag depends on the neutral density, which too is triggered by space weather.