Disappearance, recovery and patchiness of plasmaspheric hiss following two consecutive interplanetary shocks: First results Chapter uri icon

Overview

abstract

  • We present, for the first time, a plasmaspheric hiss event observed by; the Van Allen probes in response to two successive interplanetary shocks; occurring within an interval of ~2 hours on December 19,; 2015. The first shock arrived at 16:16 UT and caused disappearance of; hiss for ~30 minutes. Significant Landau damping by; suprathermal electrons followed by their gradual removal by; magnetospheric compression opposed the generation of hiss causing the; disappearance. Calculation of electron phase space density and linear; wave growth rates showed that the shock did not change the growth rate; of whistler mode waves within the core frequency range of plasmaspheric; hiss (0.1 - 0.5 kHz) during this interval making conditions unfavorable; for the generation of the waves. The recovery began at; ~16:45 UT which is attributed to an enhancement in local; plasma instability initiated by the first shock-induced substorm and; additional possible contribution from chorus waves. This time, the wave; growth rate peaked within the core frequency range (~350; Hz). The second shock arrived at 18:02 UT and generated patchy hiss; persisting up to ~19:00 UT. It is shown that an enhanced; growth rate and additional contribution from shock-induced poloidal Pc5; mode (periodicity ∼240 sec) ULF waves resulted in the excitation of hiss; waves during this period. The hiss wave amplitudes were found to be; additionally modulated by background plasma density and fluctuating; plasmapause location. The investigation highlights the important roles; of interplanetary shocks, substorms, ULF waves and background plasma; density in the variability of plasmaspheric hiss.

publication date

  • February 18, 2021

has restriction

  • closed

Date in CU Experts

  • January 28, 2022 7:34 AM

Full Author List

  • Chakraborty S; Chakrabarty D; Reeves GD; Baker DN; Claudepierre SG; Breneman AW; Hartley DP; Larsen BA

author count

  • 8

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