Asymmetry in the Terrestrial Plasma Sheet Driven by Dayside Dynamics

<p>The Interstellar Boundary Explorer (IBEX) mission continues to provide energetic neutral atom (ENA) observations of the heliosphere and Earth&#8217;s magnetosphere from a global perspective and including spatial, temporal, and energy information. Due to its orbit, IBEX routinely observes the magnetosphere from a side-viewing vantage point, with a field-of-view that is nearly perpendicular to the day-night plane. This enables the construction of composite ENA images at different energies (0.5 &#8211; 6.0 keV) for convected solar wind conditions, which provides global insights into different magnetospheric plasma regions and processes.</p> <p>Earth&#8217;s plasma sheet plays a crucial role in the global circulation of plasma throughout the magnetosphere. The structure of the plasma sheet is driven by a combination of effects including interplanetary magnetic field (IMF) and solar wind conditions, internal magnetospheric processes, and Earth&#8217;s dipole tilt angle.</p> <p>This work examines the structure of the plasma sheet in the X-Z geocentric ecliptic plane (GSE) using ENA images from IBEX. The thickness and extent of the plasma sheet is compared for conditions of prolonged northward and southward IMF. We report on a North-South asymmetry in the plasma sheet that is related to the IMF orientation and is driven by a combination of dayside magnetic reconnection effects and high dipole tilt. Results provide evidence of dayside reconnection driving plasma sheet dynamics.</p>