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At least 127 records · Page 7

How Magnetically Conjugate Atmospheres and the Magnetosphere Participate in the Formation of Low‐Energy Electron Precipitation in the Region of Diffuse Aurora

The electron precipitation in the region of the diffuse aurora should be considered as a two‐step process (Khazanov et al., 2017, https://doi.org/10.1002/2016GL072063). The first one is the interaction of plasma sheet electrons with electrostatic electron cyclotron and/or whistler waves, moving those electrons into the loss cone to precipitate in both magnetically conjugate atmospheres. The second step is the interaction of these electrons with the ionosphere and atmosphere via their elastic and nonelastic collisions and reflection (backscatter) of degraded electrons back to magnetosphere and conjugate ionospheres. This paper presents the results of a newly developed scenario of non steady‐state electron precipitation dynamics that accounts for magnetosphere‐ionosphere‐atmosphere energy interplay over the entire energy range of the plasma sheet electron population and their affiliated secondary electrons. It also studies how both magnetically conjugate auroral regions work together with the magnetosphere in the formation of electron precipitation in the region of the diffuse aurora with the energy range coverage from 1 eV up to 10 keV.

George V Khazanov↗

Auroral Electron Estimates From the Voyager 2 Plasma Observations During the Uranus Flyby and Comparisons to Earths Aurora

Introduction: We are fortunate enough to have plasma observations from the Voyager 2 flyby of Uranus in 1986. We revisit these data in the context of estimating what the auroral electrons in Uranus’ magnetosphere would look like and how they would compare to what we know about Earth’s aurora and how it is coupled to Earth’s magnetosphere. The Voyager 2 flyby of Uranus provided us with valua-ble information about the plasma environment in-side the magnetosphere of Uranus (Sittler, et al., 1987). The maximum energy of the Voyager 2 plasma instrument was 6 keV for electrons and it is clear from the data that the electron fluxes extended be-yond that range to higher energies. Future meas-urements should extend up to around 30 keV in or-der to fully capture the full electron distribution within the magnetosphere and those corresponding to the aurora. The electron temperatures were around 2 keV throughout the magnetosphere of Uranus and the densities ranged from 0.001 to 1.0 per cubic centimeter. These observed parameters will be compared to analogous structures within Earth’s magnetosphere and be used to estimate the energy and fluxes of electrons that would be observed within the auroral zones on Uranus.

R G Michell↗

On the x-ray emission in the aurora zones

The X-radiation, occurring in the aurora zone, was first revealed in the summer of 1952 [1,2] rockets above 50 km. This radiation is mainly concentrated between the 62 and 77° geomagnetic latitude, with a maximum near 67.5°. It is generated at fast electron collisions with upper atmosphere particles.

PLANET↗