loading page

Geospace Concussion: Global reversal of ionospheric vertical plasma drift in response to a sudden commencement
  • +11
  • Xueling Shi,
  • Dong Lin,
  • Wenbin Wang,
  • J. B. H. Baker,
  • James M. Weygand,
  • Michael D. Hartinger,
  • Viacheslav G. Merkin,
  • John Michael Ruohoniemi,
  • Kevin H Pham,
  • Haonan Wu,
  • Vassilis Angelopoulos,
  • Kathryn A McWilliams,
  • Nozomu Nishitani,
  • Simon George Shepherd
Xueling Shi
Virginia Polytechnic Institute and State University
Author Profile
Dong Lin
National Center for Atmospheric Research

Corresponding Author:ldong@ucar.edu

Author Profile
Wenbin Wang
Author Profile
J. B. H. Baker
Virginia Tech
Author Profile
James M. Weygand
Department of Earth, Planetary, and Space Sciences
Author Profile
Michael D. Hartinger
Space Science Institute
Author Profile
Viacheslav G. Merkin
The Johns Hopkins University Applied Physics Laboratory
Author Profile
John Michael Ruohoniemi
Virginia Tech
Author Profile
Kevin H Pham
National Center for Atmospheric Research
Author Profile
Haonan Wu
Clemson University
Author Profile
Vassilis Angelopoulos
University of California Los Angeles
Author Profile
Kathryn A McWilliams
University of Saskatchewan
Author Profile
Nozomu Nishitani
Nagoya University
Author Profile
Simon George Shepherd
Dartmouth College
Author Profile


An interplanetary shock can abruptly compress the magnetosphere, excite magnetospheric waves and field-aligned currents, and cause a ground magnetic response known as a sudden commencement (SC). However, the transient (<~1 min) response of the ionosphere-thermosphere system during an SC has been little studied due to limited temporal resolution in previous investigations. Here, we report observations of a global reversal of ionospheric vertical plasma motion during an SC on 24 October 2011 using ~6 s resolution SuperDARN ground scatter data. The dayside ionosphere suddenly moved downward during the magnetospheric compression due to the SC, lasting for only ~1 min before moving upward. By contrast, the post-midnight ionosphere briefly moved upward then moved downward during the SC. Simulations with a coupled geospace model suggest that the reversed E X B vertical drift is caused by a global reversal of ionospheric zonal electric field induced by magnetospheric compression during the SC.