The Micro‐Macro Coupling of Mass‐Loading in Symmetric Magnetic Reconnection With Cold Ions. Issue 13 (3rd July 2021)

• Record Type: Journal Article
• Authors: Spinnangr, Susanne F.; Hesse, Michael; Tenfjord, Paul; Norgren, Cecilia; Kolstø, Håkon M.; Kwagala, Norah K.; Jørgensen, Therese M.
• Is Part Of: Geophysical research letters. Volume 48:Issue 13(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-03
• Subjects: magnetic reconnection -- cold ions -- micro‐macro coupling -- simulation -- PIC; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL090690
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We investigate how magnetic reconnection is influenced by an inflow of a dense cold ion population. We compare two 2.5D Particle‐In‐Cell simulations, one containing the cold population and one without. We find that the cold population influences the reconnection process on both global and kinetic scales, and that the dominant contribution can be explained through mass‐loading. We provide an analysis of how these multiscale changes are related through kinetic processes in the ion diffusion region, the so‐called micro‐macro coupling of mass‐loading. The inertia of the cold ion population is found to be the significant link that connects the changes on different scales. The cold and warm populations exhibit counter streaming behavior when and after the ion diffusion region reorganizes itself in response to the arrival of the cold population. This signature of the cold population should be observable by spacecraft observatories such as MMS. Plain Language Summary: We investigate how magnetic reconnection is influenced by a dense inflow of cold ions. We find that the cold ions influence the reconnection process on both large and small scales, and that these are connected through the cold ion inertia. We also see cold and warm ions moving in opposite directions close to the reconnection site, which should be observable by spacecraft observatories. Key Points: Cold ions in the inflow region affect reconnection on both micro‐ and macro‐scales The micro‐macro coupling of mass‐loading is mediated by the cold ion inertia Cold and warm ions are counter streaming close to the ion diffusion region boundary