Open AccessThe Secular Variation of the Center of Geomagnetic South Atlantic Anomaly and Its Effect on the Distribution of Inner Radiation Belt Particles
Author(s) -
Ye Yuguang,
Zou Hong,
Zong Qiugang,
Chen Hongfei,
Wang Yongfu,
Yu Xiangqian,
Shi Weihong
Publication year - 2017
Publication title -
space weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 56
ISSN - 1542-7390
DOI - 10.1002/2017sw001687
Subject(s) - south atlantic anomaly , earth's magnetic field , van allen radiation belt , anomaly (physics) , secular variation , physics , geophysics , proton , altitude (triangle) , ring current , latitude , geology , geodesy , magnetic field , astronomy , magnetosphere , nuclear physics , condensed matter physics , geometry , mathematics , quantum mechanics
In this study, we carry out a comprehensive analysis of secular variation of the South Atlantic Anomaly. The center location of the South Atlantic Anomaly (SAA) is derived from the proton flux measurements of different energy channels by SAMPEX (Solar Anomalous and Magnetospheric Particle Explorer)/PET (Proton/Electron Telescope). The results are compared with National Oceanic and Atmospheric Administration/Medium Energy Proton and Electron Detector observations and the International Geomagnetic Reference Field 12 (IGRF12) geomagnetic field model. It is found that different energy protons have different behaviors while the center location of the SAA changes with altitude. The IGRF12 magnetic field can explain the observations to a limited extent. Possible reasons for the differences are discussed. It is confirmed that center location of the SAA is also affected by atmospheric density at SAMPEX altitudes. The results could be helpful for constructing inner radiation belt models.