South-Atlantic Anomaly magnetic storms effects as observed outside the International Space Station in 2008–2016

Abstract

Two Liulin type spectrometers performed measurements of the energetic particles flux outside the International Space Station (ISS) in 3 long-term periods between 2008 and 2016. The linear regression analysis is performed of 1053 averaged per day South-Atlantic anomaly (SAA) proton flux measurements from the daily Dst index. The data reveal that the SAA flux dependence from the Joule heating in the high latitudes and respectively from the neutral atmosphere density, isn't observed only in the time of the magnetic storms. This is a permanent, continues process influencing the SAA fluxes all the time. The data, obtained during the two magnetic storms in 2010 and to powerful storms of March and June 2015, were used to find and classify the following short-term magnetic storm effects: 1) The SAA proton flux maximum and area show strong decrease during the main phase of the magnetic storms. The protons losses can be caused by the collisions with the storm-enhanced neutral oxygen atoms. This hypothesis is proved by a comparison with the prediction by the NRLMSISE-00 model global neutral Oxygen density; 2) Increase of the proton flux, in the presence of solar energetic protons, is observed during the storm sudden commencements (SSC); 3) An enhanced flux of relativistic electrons is recorded in SAA during the recovery phase of the magnetic storms at L-values higher than 1.7. They migrate from the outer radiation belt. Their presence was proved by the analysis of the energy deposition spectra.