MMS Observations of Multiscale Hall Physics in the Magnetotail

Love Alm , Mats André (1) , Daniel B Graham , Yuri Khotyaintsev (1) , Andris Vaivads (2) , Charles R Chappell , Jérémy Dargent , Stephen Fuselier (3) , Stein Haaland , Benoit Lavraud (4) , Wenya Li (5) , Paul Tenfjord , Sergio Toledo-Redondo , Sarah K Vines

1 IRF - Swedish Institute of Space Physics [Uppsala / Kiruna]
2 Institutet för Rymdfysik
3 Space Science and Engineering Division [San Antonio]
4 IRAP - Institut de recherche en astrophysique et planétologie
5 NSSC - National Space Science Center [Beijing]

We present Magnetospheric Multiscale mission (MMS) observations of Hall physics in the magnetotail, which compared to dayside Hall physics is a relatively unexplored topic. The plasma consists of electrons, moderately cold ions (T ∼ 1.5 keV) and hot ions (T ∼ 20 keV). MMS can differentiate between the cold ion demagnetization region and hot ion demagnetization regions, which suggests that MMS was observing multiscale Hall physics. The observed Hall electric field is compared with a generalized Ohm's law, accounting for multiple ion populations. The cold ion population, despite its relatively high initial temperature, has a significant impact on the Hall electric field. These results show that multiscale Hall physics is relevant over a much larger temperature range than previously observed and is relevant for the whole magnetosphere as well as for other astrophysical plasma.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

Love Alm, Mats André, Daniel B Graham, Yuri Khotyaintsev, Andris Vaivads, et al.. MMS Observations of Multiscale Hall Physics in the Magnetotail. Geophysical Research Letters, In press, ⟨10.1029/2019GL084137⟩. ⟨hal-02372728⟩