Shock-induced disappearance and subsequent recovery of plasmaspheric hiss: Coordinated observations of RBSP, THEMIS and POES satellites

TitleShock-induced disappearance and subsequent recovery of plasmaspheric hiss: Coordinated observations of RBSP, THEMIS and POES satellites
Publication TypeJournal Article
Year of Publication2017
AuthorsLiu, N, Su, Z, Gao, Z, Reeves, GD, Zheng, H, Wang, Y, Wang, S
JournalJournal of Geophysical Research: Space Physics
Date Published10/2017
KeywordsChorus; interplanetary shock; Plasmaspheric Hiss; Radiation belt; substorm injection; Van Allen Probes; wave-particle interaction
AbstractPlasmaspheric hiss is an extremely low frequency whistler-mode emission contributing significantly to the loss of radiation belt electrons. There are two main competing mechanisms for the generation of plasmaspheric hiss: excitation by local instability in the outer plasmasphere and origination from chorus outside the plasmasphere. Here, on the basis of the analysis of an event of shock-induced disappearance and subsequent recovery of plasmaspheric hiss observed by RBSP, THEMIS and POES missions, we attempt to identify its dominant generation mechanism. In the pre-shock plasmasphere, the local electron instability was relatively weak and the hiss waves with bidirectional Poynting fluxes mainly originated from the dayside chorus waves. On arrival of the shock, the removal of pre-existing dayside chorus and the insignificant variation of low-frequency wave instability caused the prompt disappearance of hiss waves. In the next few hours, the local instability in the plasmasphere was greatly enhanced due to the substorm injection of hot electrons. The enhancement of local instability likely played a dominant role in the temporary recovery of hiss with unidirectional Poynting fluxes. These temporarily recovered hiss waves were generated near the equator and then propagated toward higher latitudes. In contrast, both the enhancement of local instability and the recurrence of pre-noon chorus contributed to the substantial recovery of hiss with bidirectional Poynting fluxes.
URLhttp://onlinelibrary.wiley.com/doi/10.1002/2017JA024470/full
DOI10.1002/2017JA024470
Short TitleJ. Geophys. Res. Space Physics


Page Last Modified: October 24, 2017