Open AccessNightside detached auroras due to precipitating protons/ions during intense magnetic storms
Author(s) -
Zhang Y.,
Paxton L. J.,
Morrison D.,
Wolven B.,
Kil H.,
Wing S.
Publication year - 2005
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004ja010498
Subject(s) - plasmasphere , physics , ring current , proton , electron precipitation , ion , geomagnetic storm , ionosphere , thermosphere , magnetosphere , van allen radiation belt , precipitation , geophysics , magnetopause , plasma , atomic physics , atmospheric sciences , solar wind , meteorology , nuclear physics , quantum mechanics
Nightside detached auroras (NDA) during intense magnetic storms are studied by using FUV image data from Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics (TIMED)/Global Ultraviolet Imager (GUVI), Imager for Magnetopause‐to‐Aurora Global Exploration (IMAGE)/FUV, and particle data from DMSP/SSJ/4 instruments. We found that NDA are caused by proton/ion precipitation only. Thin arc‐shaped NDA are very likely due to soft (<1 keV) proton/ion precipitation. Thick or patch‐shaped NDA are caused by energetic (∼10 keV) proton/ion precipitation. All the cases indicate that the NDA were observed when Dst was less −130 nT. More specifically, the NDA occurred during recovery or the lowest Dst period for each intense storm. The magnetic latitudes of the NDA are between 45° and 55° ( L shell: 2.0–3.0). We found that the latitude location of the NDA is quasi‐linearly correlated with Dst . The magnetic local time (MLT) of the NDA ranges from 1930 to 0300. All the facts indicate that the source of the NDA is the trapped protons/ions in the ring current. Precipitation of the trapped protons/ions is caused by an interaction between the perpendicularly heated ring current particles and the cold/dense plasma at the plasmapause.