NOAA POES and MetOp particle observations during the 17 March 2013 storm

The above 1 MeV electrons disappear in the storm main phase, but appears with increased intensity in the recovery phase. They are limited to the invariant latitude region 50∘ to 62∘. The lower energy electrons penetrate deeper into the magnetosphere. During geomagnetic storms a Storm Time Equatorial Belt (STEB) of energetic neutral atoms and ions is found to exist at low altitudes around the geomagnetic equator. Their source is the RC protons existing at larger L-values. The STEB appears first in the midnight/evening sector and then later in the morning sector largely consistent with the drift of the RC ions and in accordance with results from ground based magnetic observations. During the main phase of the storm, the outer part of the RC will experience magnetopause shadowing and will be lost at the magnetopause. Maximum particle injection into the ring current is associated with the most rapid fall in Dst. The maximum STEB intensity is associated with minimum Dst and strongest RC.