Séminaires

Eric Buchlin (IAS): Beware of the solar storm! (1222-RCSB-08)

Europe/Paris
Description

 In our daily experience, the Sun is a quiet companion that constantly                                                                                    
     provides us with light and warmth. However, observations of the                                                                                          
     different structures in its atmosphere show that much activity takes                                                                                     
     place. Waves and turbulence heat the magnetized plasma of the corona to                                                                                  
     more than a million kelvins. The magnetic field produces sunspots and                                                                                    
     active regions, and sustains relatively cool and dense prominences in                                                                                    
     the hot and tenuous corona, which expands towards a continuous stream of                                                                                 
     solar wind. More dramatically, instabilities of the magnetic field lead                                                                                  
     to eruptions, which can have important consequences on the heliosphere                                                                                   
     in general and on Earth in particular, due to short-term variability in                                                                                  
     light emission, magnetic field, and accelerated particles. In an                                                                                         
     increasingly technological society, human activities can be affected and                                                                                 
     space weather services, including the prediction of eruptions, become a                                                                                  
     necessity.