Fig. 11

Summary plot using Geotail observations (a) showing dependence of O⁺/H⁺ energy density ratio on Sym-H or Dst in the ring current and the plasma sheet. Red, blue and green data points correspond to the energy density ratio reported from previous studies and references there in Nosé et al. (2005, 2001, 2003), respectively. The data points represented in black are outcome from this study. Black vertical dashed line at 0 nT is the boundary for quiet interval. b The energy density variation of O⁺ ions with respect to Sym-H or Dst. The blue data points correspond to the energy density values measured by Nosé et al. (2001) while red data set corresponds to the energy density values measured in this study. The quiet interval is considered above − 25 nT, shown by black vertical dashed line