Near-Earth injection of MeV electrons associated with intense dipolarization electric fields Van Allen Probes observations

Near-Earth injection of MeV electrons associated with intense dipolarization electric fields : Van Allen Probes observations

Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injectio...

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Publié dans:Geophysical research letters. - 1984. - 42(2015), 15 vom: 16. Aug., Seite 6170-6179
Auteur principal: Dai, Lei (Auteur)
Autres auteurs: Wang, Chi, Duan, Suping, He, Zhaohai, Wygant, John R, Cattell, Cynthia A, Tao, Xin, Su, Zhenpeng, Kletzing, Craig, Baker, Daniel N, Li, Xinlin, Malaspina, David, Blake, J Bernard, Fennell, Joseph, Claudepierre, Seth, Turner, Drew L, Reeves, Geoffrey D, Funsten, Herbert O, Spence, Harlan E, Angelopoulos, Vassilis, Fruehauff, Dennis, Chen, Lunjin, Thaller, Scott, Breneman, Aaron, Tang, Xiangwei
Format: Article
Langue:English
Publié: 2015
Accès à la collection:Geophysical research letters
Sujets:Journal Article electric fields radiation belt electrons substorm dipolarization substorm injection
Description
Résumé:Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L ∼ 5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ∼40 s and a dispersionless injection of electrons up to ∼3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons
Description:Date Revised 25.03.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:0094-8276