This Is Auburn

Show simple item record

A study of the electromagnetic proton cyclotron instability as a generation mechanism for EMIC waves in the Earth's magnetosphere using SCATHA data


Metadata FieldValueLanguage
dc.creatorNguyen, Son T.
dc.creatorPerez, J. D.
dc.creatorFennell, Joseph F.
dc.date.accessioned2020-06-16T19:25:38Z
dc.date.available2020-06-16T19:25:38Z
dc.date.created2007-12
dc.identifier10.1029/2007JA012291en_US
dc.identifier.urihttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007JA012291en_US
dc.identifier.urihttp://hdl.handle.net/11200/49883
dc.description.abstractUsing 59 days of magnetic field data from SCATHA, a study of the electromagnetic proton cyclotron instability as a generation mechanism for EMIC waves in the Earth's magnetosphere has been conducted. From 1181 events found, we selected 373 events that were not influenced by the presence of He+ and O+ ions, i.e.,events with frequency above the local He+ cyclotron frequency and that had all the required accompanying data. These events occurred in all magnetic local times (MLT) sectors, with L ranging from 5.6 to 8.1 and magnetic latitudes (MLAT) from -13.7 degrees to 15.6 degrees. Assuming a pure proton plasma, the proton temperature anisotropy, Ap, is determined from the maximum normalized frequency at which power is emitted. Using measured parameters and estimated total number density, the convective growth rate, S, of Electromagnetic Ion Cyclotron (EMIC) waves as a function of frequency depends only on the parallel proton temperature, T-parallel to. Matching the observed peak in the frequency spectrum and the calculated peak in S allows the determination of T-parallel to and the proton perpendicular temperature, T-perpendicular to, for each event. Analysis of the results yields a new empirical expression for A(p) as a function of the hot proton parallel beta, beta(parallel to h), and the maximum value of the wave temporal growth rate. The relationship between A(p) and beta(parallel to h) is consistent with theoretical predictions. The dependence of A(p) on T-parallel to is consistent with the expectation that the free energy source of EMIC waves is energetic protons with T-perpendicular to > T-parallel to.en_US
dc.formatPDFen_US
dc.publisherAMER GEOPHYSICAL UNIONen_US
dc.relation.ispartofJOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICSen_US
dc.relation.ispartofseries2169-9380en_US
dc.subjectMAGNETIC PULSATIONS; SYNCHRONOUS ORBIT; PLASMA; MAGNETOSHEATH; ANISOTROPY; PARTICLE; FREQUENCY; DENSITY; MODEL; O+en_US
dc.titleA study of the electromagnetic proton cyclotron instability as a generation mechanism for EMIC waves in the Earth's magnetosphere using SCATHA dataen_US
dc.typeTexten_US
dc.type.genreJournal Article, Academic Journalen_US
dc.citation.volume112en_US
dc.citation.issueA12en_US
dc.description.statusPublisheden_US

Files in this item

Show simple item record