Investigating the Occurrence of Magnetic Reconnection at Jupiter's Dawn Magnetopause During the Juno Era

Abstract

AbstractIn this study, observations from the Jovian auroral distributions experiment, Jupiter energetic particle detector instrument, and Magnetic field investigation instruments on Juno are used to identify signatures of magnetic reconnection at Jupiter's dawn magnetopause and relate these signatures to the local plasma environment. Magnetopause crossings occurred between 73–114 Jovian radii and 4.3–6.2 magnetic local time at low latitudes. Reconnection signatures include plasma energization and ion velocity enhancements resembling reconnection jets. We test for diamagnetic suppression which considers the magnetic shear and plasma beta (β) before and after a magnetopause crossing. Findings show that a large majority of these dawn magnetopause crossings at Jupiter have a low likelihood for local magnetic reconnection (are diamagnetically suppressed) because of high delta β values and/or low magnetic shear angles across the magnetopause boundary. These crossings exhibit no evidence of local reconnection while crossings that are not diamagnetically suppressed show multiple signatures of reconnection, adhering to the Swisdak relation.