EGU26-1430, updated on 13 Mar 2026
https://doi.org/10.5194/egusphere-egu26-1430
EGU General Assembly 2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
Oral | Wednesday, 06 May, 16:15–16:25 (CEST)
 
Room 1.85/86
Shock Dayside Auroras and Shock-Substorms: Internal Magnetospheric Shocks
Bruce Tsurutani1, Yasuhito Narita2, and Rajkumar Hajra3
Bruce Tsurutani et al.
  • 1Retired from Jet Propulsion Laboratory, Caltech, Space physics, Pasadena, United States of America (bruce.tsurutani@gmail.com)
  • 2Technisches Universitaet Braunschweig, Braunschweig, Germany
  • 3University of Science and Technology of China, Hefei, China

Interplanetary shocks cause dayside auroras and can cause nighttime substorms.  Both phenomena occur within minutes of the shock impingement onto the magnetosphere.  The nightside substorms occur if there is solar wind energy preloading within ~3 hrs prior to shock impingement.  If there is no energy preloading, a substorm will not occur.  There will only be the dayside aurora.  In one shock-substorm examined (GRL 2025) the auroral onset occurred at L ~6, indicating that magnetic reconnection was not the mechanism for substorm onset.  Possible specific trigger mechanisms will be discussed.

GRL, 26, 8, 1097, 1999; GRL 106, A9, 18957, 2001; Surv. Geo., 22, 101, 2001; ASR, 31, 4, 1063, 2003; GRL, 52, 2025 https:/doi.org/10.1029/2025GL115509.

How to cite: Tsurutani, B., Narita, Y., and Hajra, R.: Shock Dayside Auroras and Shock-Substorms: Internal Magnetospheric Shocks, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1430, https://doi.org/10.5194/egusphere-egu26-1430, 2026.