ISO 16457:2022 pdf download – Space environment (natural and artificial) — The Earth’s ionosphere model — International reference ionosphere (IRI) model and extensions to the plasmasphere. 3.4 solar activity series of processes occurring in the Sun’s atmosphere which affect the interplanetary space and the Earth Note 1 to entry: The level of solar activity is characterized by indices. 3.5 ionospheric storm storm lasting about a day, documented by depressions and/or enhancements of the ionospheric electron density during various phases of the storm Note 1 to entry: Ionospheric storms are the ultimate result of solar flares or coronal mass ejections, which produce large...