Evolution of kinklike fluctuations associated with ion pickup within reconnection outflows in the Earth's magnetotail

TL;DR

This study investigates ion pickup and kink-like fluctuations during magnetic reconnection in Earth's magnetotail, revealing how these oscillations evolve and propagate over large distances during substorms.

Contribution

It provides detailed observations of the generation and evolution of kink-like oscillations associated with ion populations during reconnection events.

Findings

Kink oscillations can propagate at least 25,000 km from the reconnection site.

Oscillations are driven by different ion populations within the outflow region.

Kink-like fluctuations evolve and fade over a distance of 70,000 km.

Abstract

Magnetic reconnection (MR) in Earth's magnetotail is usually followed by a systemwide redistribution of explosively released kinetic and thermal energy. Recently, multispacecraft observations from the THEMIS mission were used to study localized explosions associated with MR in the magnetotail so as to understand subsequent Earthward propagation of MR outbursts during substorms. Here we investigate plasma and magnetic field fluctuations/structures associated with MR exhaust and ion-ion kink mode instability during a well documented MR event. Generation, evolution and fading of kinklike oscillations are followed over a distance of 70 000 km from the reconnection site in the midmagnetotail to the more dipolar region near the Earth. We have found that the kink oscillations driven by different ion populations within the outflow region can be at least 25 000 km from the reconnection site.