The Response of the Energy Content of the Outer Electron Radiation Belt to Geomagnetic Storms
Abstract
Using the data from the Van Allen Probe‐A spacecraft, the variability of the total outer radiation belt (2.5 300 keV) is investigated for the first time during 51 isolated storms spanning from October 2012 to May 2017. The statistical results show that the TRBEEC exhibits no change in 20% of the storms and gets enhanced during 80% of them. The subrelativistic electrons (300–500 keV) and relativistic electrons (0.5–2.0 MeV) equally contribute to the TRBEEC during the main phases, while in the recovery phases, the relativistic electrons contribute up to 80% of the TRBEEC. The results of the superposed epoch analysis of the solar wind parameters and geomagnetic indices indicate that the TRBEEC enhancement events preferably occur during the prolonged southward interplanetary magnetic field period when the solar wind‐magnetosphere coupling is more efficient. Meanwhile, the high AE index with intense injections of several hundreds of kiloelectron volt seed electrons also favors the increase of the TRBEEC. Case study shows that there is a localized growing phase space density peak around L* = 4.3 and the chorus wave energy and the gain of TRBEEC are on the same order of magnitude, which may suggest that the enhancement of the TRBEEC is the consequence of the chorus acceleration. Understanding the energy budget of the outer zone electrons can provide more insight into the energy transfer from plasma waves to the energetic electron population, especially for revealing the underlying physics of the energization of outer radiation belt electrons via chorus wave acceleration.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2018
- Source ID
- 10.1029/2018ja025475
Entities
People
- Binbin Ni
- Lun Xie
- Lunjin Chen
- S. Y. Fu
- Ying Xiong
- Z. Y. Pu
Organizations
- Air Force Office of Scientific Research
- National Natural Science Foundation of China
- National Science Foundation
- Peking University
- University of Texas at Dallas
- Wuhan University