27 July 2015 to 21 August 2015
Nordita, Stockholm
Europe/Stockholm timezone

Previously hidden low-energy ions and a new length-scale in magnetic reconnection

Not scheduled
132:028 (Nordita, Stockholm)

132:028

Nordita, Stockholm

Poster Workshop, August 10-14

Speaker

Prof. Mats André (Swedish Institute of Space Physics, Uppsala)

Description

Magnetospheric ions with energies less than tens of eV originate from the ionosphere. The low energy indicates the origin of the plasma but also severely complicates detection of the positive ions onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of volts. We discuss some methods to observe low-energy ions, including a recently developed technique based on the detection of the wake behind a charged spacecraft in a supersonic flow. We find that low-energy ions are common just inside the magnetopause. During magnetopause magnetic reconnection events, these low-energy ions remain magnetized down to smaller length-scales than the hot (keV) ions, introducing a new scale. The Hall currents, carried by electrons, will be partially cancelled by magnetized low-energy ions. We use observations by the Cluster spacecraft at the Earth’s magnetopause to verify that when a mixture of ions of very different temperatures is present in reconnecting plasmas, the microphysics related to the Hall effect is significantly modified.

Primary author

Prof. Mats André (Swedish Institute of Space Physics, Uppsala)

Co-authors

Dr Andris Vaivads (Swedish Institute of Space Physics, Uppsala) Dr Sergio Toledo-Redondo (Swedish Institute of Space Physics, Uppsala) Dr Yuri Khotyaintsev (Swedish Institute of Space Physics, Uppsala)

Presentation materials