Explosions on the Sun and effects on the Earth's environment: a new discipline called Space Weather

by Dr Igino Coco (Istituto Nazionale di Geofisica e Vulcanologia (INGV))

Tuesday 26 Nov 2024, 10:00 → 12:00 Europe/Rome

M. B. Ceolin meetin room

A number of explosive phenomena occur in the atmosphere of the Sun: solar flares, eruptions and filaments, coronal mass ejections. These phenomena inject in the solar system a huge amount of energy in the form of electromagnetic waves (in their full spectrum of wavelengths from radio to gamma rays), high energy protons and electrons and bubbles of low energy "plasma", i.e. an ionized gas of protons and electron which carries with it the long distance expansion of the solar magnetic field. Electrically charged particles interact with the Earth's magnetic field generating electric currents in the higher layers of the Earth's atmosphere or directly penetrating in the atmosphere. The X-ray radiation from the solar flares, on the other hand, causes strong ionisation in the upper atmosphere. All these effects could be very harmful for a number of technological devices and applications: from satellites circuits and instrumentations, directly affected by the high energy particles from the Sun, to radio communications and accurate GPS positioning and timing, as the propagation conditions of the radio waves in the upper atmosphere are strongly affected by the additional ionisation. Moreover, the strongest perturbations of the geomagnetic field could even induce electric currents at ground that propagate in the power grids causing overloads and blackouts. A new discipline has been grown in the last decades, which tries to model and predict the effects at ground of the solar perturbations: the Space Weather!