Multi-space observations of the storm sudden commencement (September 2017) and its effect on the geomagnetic field

The present study describes the results of the magnetic field perturbations associated with the storm sudden commencement (SSC) during the geomagnetic storm in September 2017, and the shock-induced electron depletions in geosynchronous orbit. Multi-space observations were detected by ten various satellites with different orbits at distinct locations with a comprehensive view inside the magnetosphere. Magnetospheric Multiscale (MMS1) satellite is the only equipment that observed the SSC waveform as a sharp peak inside the daytime plasmasphere. Depending on SSC events of this storm, the largest Δ B_H amplitude for SSC was at different satellite locations in the local noon sector (MLT = 11-15) and at L- shell values from 2 to 11 R_E . The L-shell value has almost a linear relation with the delay time of the SSC onset and a reverse one with the Δ B_H amplitude at the nightside. The dominated rise time value is 2 min at nightside. IP shocks of SSC events during this storm generate shock-induced relativistic electron depletions.