Relative contribution of electrons to the stormtime total ring current energy content

Abstract

[1] We evaluate the relative importance of stormtime ring current electrons to protons by calculating the energy content ratio of electrons to protons for typical ring current energies inferred from observations and simulations. We analyze Explorer 45 measurements taken around the minimum Dst(=À171 nT) of the 17 December 1971 storm. We simulate the electron and proton ring current energy content during a hypothetical storm using drift-loss simulations. From the data analysis, we find that electrons with energies of $1 -50 keV and protons with energies of $10-200 keV contribute the most to the corresponding particle energy content. From both observations and simulations, the ring current electrons contribute only $1% as much energy content as ring current protons during quiet times. However, this ratio increases to $8-19% during storm main phase. Thus, the ring current electrons can contribute significantly to the ring current energy content during storms. Citation: Liu, S., M. W. Chen, J. L. Roeder, L. R. Lyons, and M. Schulz (2005), Relative contribution of electrons to the stormtime total ring current energy content, Geophys. Res. Lett., 32, L03110,

How the Earth's inner magnetosphere works: An evolving picture

“…Later measurements showed that ions between $10 and 200 keV are the main contributors to the ring current (e.g., Williams (1980)), while electrons of similar energies make a smaller contribution (Liu et al, 2005).…”

Effect of solar wind pressure enhancements on storm time ring current asymmetry

“…Electrons in the same energy range also make a contribution to the energy density of the ring current, but this contribution is well below that of ions [Frank, 1967;Lyons and Williams, 1975]. A recent study showed that electrons can contribute about 16% to the energy content of the ring current [Liu et al, 2005]. In this paper we only consider the contribution of ions to the ring current and neglect that of the electrons when we discuss the formation of the asymmetric ring current and effects of solar wind dynamic pressure on the asymmetry.…”

The effect of ring current electron scattering rates on magnetosphere‐ionosphere coupling

“…The self‐consistent version of HEIDI produced a smaller D s t ∗ drop with little variation of the results between simulations using different τ max values. This was to be expected, as electrons generally constitute a small percentage of the ring current energy density [ Frank , ; Liu et al , ; Jordanova and Miyoshi , ]. There is no difference between these runs before the storms, since the aurora during this time was derived from the same empirical model.…”