Comparison study of ring current simulations with and without bubble injections. Issue 1 (25th January 2016)

• Record Type: Journal Article
• Authors: Yang, Jian; Toffoletto, Frank R.; Wolf, Richard A.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 1(2016:Jan.)
• Page Start: 374
• Page End: 379
• Publication Date: 2016-01-25
• Subjects: bursty bulk flows -- bubble injections -- entropy; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2015JA021901
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: For many years, stand‐alone ring current models have been successfully producing storm time ring current enhancements without specifying explicit localized transient injections along their outer boundaries. However, both observations and simulations have suggested that the frequent burst flows or bubble injections can contribute substantially to the storm time ring current energy. In this paper, we investigate the difference in the spatial and temporal development of the ring current distribution with and without bubble injections using the Rice Convection Model‐Equilibrium. The comparison study indicates that the simulation with bubble effects smoothed out along geosynchronous orbit can predict approximately the same large‐scale ring current pressure distribution and electric potential pattern as the simulation with bubble effects included. Our results suggest that the increase of the hot plasma population along geosynchronous orbit can be envisaged as an integrated effect of bubble injections from the near‐Earth plasma sheet. However, the observed fluctuations in the plasma population and electric field can only be captured when the mesoscale injections are included in the simulation. We also confirmed again that adiabatic convection of fully populated flux tubes cannot inject the ring current from the middle plasma sheet. The paper provides a justification for using stand‐alone ring current models in the inner magnetosphere to simulate magnetic storms, without explicit consideration of bubbles and magnetic buoyancy effects inside geosynchronous orbit. Key Points: Bubbles are the main source of the ring current for intense storms Including and excluding bubbles inside GEO are equivalent in producing large‐scale ring current Increase of hot plasma population along GEO is an integrated effect of bubble injections