Solar variability
The measurements made from space by the HF/NIMBUS, ACRIM/SMM-UARS, VIRGO/SoHO radiometers, during the last three activity cycles, have shown that the total solar radiation varies in phase with the magnetic activity of the Sun. The study of phenomena that determine the variability of the Sun, and the acquisition of data useful for its study, are carried out by INAF, in collaboration with research groups at the Universities of Rome "Tor Vergata" and Calabria, and the INGV-Rome.