Fig. 6: Electron phase-space dynamics and comparison of chirping rates upstream from the equator.
a Variation of \({\omega }_{tr}^{2}/{R}_{1},-{R}_{2}/{R}_{1}\), and R as a function of s. Panels b–g show the electron phase-space (v∥-ζ) distribution between s/de = −0.05 and −0.1. Panel h displays the ratio of theoretical chirping rates to the chirping rate from simulation between s/de = −0.05 and 0 for the wave event at Mars. The nonlinear chirping rate is estimated using the general definition of R for off-equatorial locations, with R = 0.5 and 0.6. The chirping rate from inhomogeneity is estimated using s0/de = −0.09 and −0.1.
