Drift of the South Atlantic Anomaly over Solar Cycles 22-24

Abstract:

Near Brazil, a weakened region of Earth’s magnetic field allows energetic particles from the Van Allen radiation belts to travel close to Earth’s surface. This region, called the South Atlantic Anomaly, varies slowly in geospatial location over the course of many years. We present a methodology to quantify the location of the South Atlantic Anomaly using energetic proton rates measured by sensors onboard the SAMPEX spacecraft. We examine the spatial variability of the SAA over a period spanning nearly two solar cycles. SAMPEX, which was in a low Earth high inclination orbit, provided high quality data from the time of its launch in 1992 to its re-entry in 2012.