Dawn-Dusk Asymmetry of Plasma Flow in Jupiter's Middle Magnetosphere Observed by Juno
Abstract
Based on plasma observations from Juno's JADE instrument and forward modeling, we investigate the dawn-dusk asymmetries within Jupiter’s magnetosphere between 10-40 RJ. On the dawnside, the flux tubes are depleted characterized by low density and near rigid-corotation velocity, with a low temperature and thin plasma sheet. On the duskside, the flux tubes are assimilated characterized by high density and sub-corotation velocity, with a hotter and thicker plasma sheet. Super-corotating hot inflows originating from reconnection events are identified in the pre-dawn sector. These observations are consistent with the Vasyliunas cycle, suggesting it operates in a region closer to Jupiter than previous studies suggested. Outflows are locally coupled with swept-back magnetic fields and are frequently observed near midnight. Inflows are locally coupled with swept-forward fields with higher temperatures. The discernible temperature difference between inflows and outflows reveals their distinct origins. Plasma beta increases with radial distance, suggesting increased instabilities at larger distances.