Multi-Step Dst Development and Ring Current Composition Changes During the 4-6 Jun 1991 Magnetic Storm
Abstract
The 4-6 June 1991 magnetic storm during solar maximum conditions is analyzed to investigate two observed features of magnetic storms: (1) ring current composition changes strongly correlated with Dst changes; and (2) multi-step ring current development. A kinetic ring current drift-loss model, driven by dynamic fluxes at the nightside outer boundary, simulated this storm interval. The majority of ions in the partial ring current pass through the inner magnetosphere on open drift paths before exiting the dayside magnetopause. Losses at the magnetopause account for the fast decay during the early recovery of the storm. It is demonstrated that density and composition changes of the inner plasma sheet are transmitted along open drift paths directly into the inner magnetosphere. When ring current drift paths are open to the magnetotail (main and early recovery phases), changes in the plasma sheet drive changes in the ring current characteristics. This accounts for the ring current composition changes correlated with Dst. It is found that the early intensifications are swept out of the magnetosphere by enhanced convection and do not precondition the system. Higher plasma sheet densities and enhanced convection produced intensifications associated with later Dst minima.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 2001
- Accession Number
- ADA401096
Entities
People
- C. R. Clauer
- J. Ridley
- J. U. Kozyra
- M. F. Thomsen
- Michael W. Liemohn
Organizations
- The Aerospace Corporation