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Title: Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

In this study by determining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations (>1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly comparing efficient and inefficient acceleration events, we clearly show that prolonged southward Bz, high solar wind speed, and low dynamic pressure are critical for electron acceleration to >1 MeV energies in the heart of the outer radiation belt. We also evaluate chorus wave evolution using the superposed epoch analysis for the identified efficient and inefficient acceleration events and find that chorus wave intensity is much stronger and lasts longer during efficient electron acceleration events, supporting the scenario that chorus waves play a key role in MeV electron acceleration.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. UCLA, Los Angeles, CA (United States)
  2. Univ. of Colorado, Boulder, CO (United States)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. NASA Goddard Space Flight Center, Greenbelt, MD (United States)
  5. Univ. of New Hampshire, Durham, NH (United States)
  6. Space Hazard Applications LLC, Golden, CO (United States)
Publication Date:
OSTI Identifier:
1236776
Report Number(s):
LA-UR--15-27787
Journal ID: ISSN 0094-8276
Grant/Contract Number:
NNX11AD75G; NNX14AN85G; NNX11AR64G; NNX13AI61G; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 42; Journal Issue: 17; Journal ID: ISSN 0094-8276
Publisher:
American Geophysical Union
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES