Foster J. C., P. J. Erickson, D. N. Baker, S. G. Claudepierre, C. A. Kletzing, W. Kurth, G. D. Reeves, S. A. Thaller, H. E. Spence, Y. Y. Shprits, J. R. Wygant, (2014), Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations, Geophysical Research Letters, 41, 20-25, doi:10.1002/2013GL058438

Abstract

Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (>2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased >90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere.

Authors (sorted by name)

Baker Claudepierre Erickson Foster Kletzing Kurth Reeves Shprits Spence Wygant

Journal / Conference

Geophysical Research Letters

Acknowledgments

We thank J. Vierinen for help in obtaining the Scandinavian sector riometer data and A. Jaynes and M. Henderson for making REPT L* and phase space density data available to assist in this study. Work at MIT Haystack Observatory was supported by a Van Allen Probes subaward from the University of Minnesota to the Massachusetts Institute of Technology. Work at the University of Colorado and University of New Hampshire was supported by RBSP‐ECT funding provided by JHU/APL contract 967399 under NASA's Prime contract NAS5‐01072. Y.Y.S. acknowledges support from NASA NNX10AK99G, NNX13AE34G, NNX09AF51G, and NSF AGS‐1203747 grants. All Van Allen Probes data used are publicly available at www.rbsp‐ect.lanl.gov.

Grants

967399 AGS‐1203747 NAS5‐01072 NNX09AF51G NNX10AK99G NNX13AE34G

Bibtex

@article{doi:10.1002/2013GL058438,
author = {Foster, J. C. and Erickson, P. J. and Baker, D. N. and Claudepierre, S. G. and Kletzing, C. A. and Kurth, W. and Reeves, G. D. and Thaller, S. A. and Spence, H. E. and Shprits, Y. Y. and Wygant, J. R.},
title = {Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations},
journal = {Geophysical Research Letters},
volume = {41},
number = {1},
pages = {20-25},
year={2014},
keywords = {Relativistic Electrons, Substorm, Radiation Belts, Prompt Energizations},
doi = {10.1002/2013GL058438},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL058438},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2013GL058438},
abstract = {Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (>2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased >90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere.}
}