loading page

Rapid Auroral Wandering During the Laschamps Event
  • +4
  • Agnit Mukhopadhyay,
  • Sanja Panovska,
  • Michael Liemohn,
  • Natalia Ganushkina,
  • Ilya Usoskin,
  • Michael Balikhin,
  • Daniel Welling
Agnit Mukhopadhyay
University of Michigan Ann Arbor

Corresponding Author:[email protected]

Author Profile
Sanja Panovska
Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences
Author Profile
Michael Liemohn
University of Michigan
Author Profile
Natalia Ganushkina
University of Michigan Ann Arbor
Author Profile
Ilya Usoskin
University of Oulu
Author Profile
Michael Balikhin
Univ Sheffield
Author Profile
Daniel Welling
University of Texas at Arlington
Author Profile


41 thousand years ago, the Laschamps geomagnetic excursion caused Earth’s geomagnetic field to drastically diminish to ~4% of modern values and modified the geomagnetic dipole axis. While the impact of this geomagnetic event on environmental factors and human lifestyle has been contemplated to be linked with modifications in the geospace environment, no concerted investigation has been conducted to study this until recently. We present an initial investigation of the global space environment and related plasma environments during the several phases of the Lachamps event using an advanced multi-model approach. We use recent paleomagnetic field models of this event to study the paleomagnetosphere with help of the global magnetohydrodynamic model BATS-R-US. Here we go beyond a simple dipole approximation but consider a realistic geomagnetic field configuration. The field is used within BATS-R-US to generate the magnetosphere during discrete epochs spanning the peak of the event. Since solar conditions have remained fairly constant over the last ~100k years, modern estimates of the solar wind were used to drive the model. Finally, plasma pressure and currents generated by BATS-R-US at their inner boundary are used to compute auroral fluxes using a stand-alone version of the MAGNIT model, an adiabatic kinetic model of the aurora. Our results show that changes in the geomagnetic field, both in strength and the dipole tilt angle, have profound effects on the space environment and the ensuing auroral pattern. Magnetopause distances during the deepest phase of the excursion match previous predictions by studies like Cooper et al. (2021), while high-resolution mapping of magnetic fields allow close examination of magnetospheric structure for non-dipolar configurations. Temporal progression of the event also exhibits rapid locomotion of the auroral region over ~250 years along with the movement of the geomagnetic poles. Our estimates suggest that the aurora extended further down, with the center of the oval located at near-equatorial latitudes during the peak of the event. While the study does not find evidence of any link between geomagnetic variability and habitability conditions, geographic locations of the auroral oval coincide with early human activity in the Iberian peninsula and South China Sea.