Electron Heat Fluxes Generated by Intense Whistler Waves at the Upper Ionospheric Altitudes. Issue 9 (7th September 2022)

• Record Type: Journal Article
• Authors: Khazanov, George V.; Ma, Qianli; Chu, Mike
• Is Part Of: Journal of geophysical research. Volume 127:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-07
• Subjects: magnetospheric whistler waves as an implicit source of cold electron heating -- electron heat fluxes -- magnetosphere‐ionosphere coupling; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2022JA030753
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: Magnetospheric whistler waves, chorus and hiss, can't provide the resonance heating of the core electron plasma population. However, these whistler‐mode branches, can implicitly participate in the heating processes of the core plasma thermal electron population by triggering the electron precipitation over a broad energy range from the magnetosphere and subsequent atmospheric ionization processes leading to the production of superthermal electron population. These superthermal electrons play a large role in the magnetosphere‐ionosphere‐atmosphere energy interplay with participation of both magnetically conjugate hemispheres, and their Coulomb interaction with background magnetospheric thermal electrons. Using strong hiss and chorus wave events measured by the Van Allen Probes and SuperThermal Electron Transport code, we evaluate the formation of electron heat fluxes at the upper ionospheric altitudes and discuss their consequences on the formation of electron temperature. It is found that chorus and hiss waves that initiate the precipitation of magnetospheric electrons with energies below 30 keV and the follow‐up production of secondary electrons play an important role in the energy balance of ionosphere‐magnetosphere system. Plain Language Summary: Electron heat flux that comes from the magnetosphere to the upper ionospheric altitudes controls the value of electron temperature in the core plasma, and, as a result, the total electron density content that is required for different kinds of space weather applications. This paper offers the new mechanism of electron heat flux formation that is based on wave‐particle interaction processes that include whistler waves: hiss and chorus. These waves can't directly heat the cold magnetospheric electrons. They, however, resonate with high energy magnetospheric electrons initiating precipitation into the atmospheres of magnetically conjugate regions and, as result, their multiple passes between the northern and southern hemispheres. High energy electron interactions with the ionospheric neutral populations lead to the production of the secondary electrons escaping back to the magnetospheric altitudes where they become trapped and move between the points of reflection. These electrons, as well as degraded primary precipitated electrons, interact with the core cold magnetospheric electrons continuously losing their energy via Coulomb collisional processes and form the electron heat flux that defines electron temperature at upper ionospheric altitudes. The newly suggested mechanism plays a very important role in the energy balance of ionosphere‐magnetosphere system and must be considered in the ionospheric space weather simulations. Key Points: Magnetospheric hiss and chorus waves is an implicit heat source of the cold electrons in ionosphere and magnetosphere SuperThermal Electron Transport simulations show the electron heat flux formation due to whistler waves through magnetosphere‐ionosphere energy interplay Our model evaluates the elevated upper ionospheric electron temperature driven by strong whistler waves in magnetosphere