Premium
Magnetic Local Time‐Resolved Examination of Radiation Belt Dynamics during High‐Speed Solar Wind Speed‐Triggered Substorm Clusters
Author(s) -
Rodger Craig J.,
Turner Drew L.,
Clilverd Mark A.,
Hendry Aaron T.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl083712
Subject(s) - substorm , magnetopause , solar wind , physics , van allen radiation belt , geophysics , earth's magnetic field , local time , electron , flux (metallurgy) , computational physics , plasma , magnetosphere , magnetic field , statistics , mathematics , quantum mechanics , materials science , metallurgy
Particle observations from low Earth orbiting satellites are used to undertake superposed epoch analysis around clusters of substorms, in order to investigate radiation belt dynamical responses to mild geomagnetic disturbances. Medium energy electrons and protons have drift periods long enough to discriminate between processes occurring at different magnetic local time, such as magnetopause shadowing, plasma wave activity, and substorm injections. Analysis shows that magnetopause shadowing produces clear loss in proton and electron populations over a wide range of L ‐shells, initially on the dayside, which interacts with nightside substorm‐generated flux enhancements following charge‐dependent drift directions. Inner magnetospheric injections recently identified as an important source of tens to hundreds keV electrons at low L ( L < 3 ), occurring during similar solar wind‐driving conditions as recurrent substorms, show similar but more enhanced geomagnetic AU‐index signatures. Twofold increases in substorm occurrence at the time of the sudden particle enhancements at low L shells (SPELLS) suggest a common linkage.