Global impacts of a Foreshock Bubble: Magnetosheath, magnetopause and ground-based observations

摘要: Using multipoint observations we show, for the first time, that Foreshock Bubbles (FBs) have a global impact on Earth’s magnetosphere. We show an FB, transient kinetic phenomenon due to interaction of backstreaming suprathermal ions with discontinuity, modifies total pressure upstream bow shock showing decrease within FB’s core and sheath regions. Magnetosheath plasma is accelerated towards intersection current sheet resulting in fast, sunward, flows as well outward motion magnetopause. Ground-based magnetometers also signatures this magnetopause simultaneously across at least 7 hours magnetic local corresponding distance 21.5 RE transverse Sun-Earth line along These observed impacts FB are agreement previous simulations stark contrast known localised, smaller scale eects Hot Flow Anomalies (HFAs).