This project will investigate the large-scale properties and consequences of magnetic merging processes (reconnection) at the high-latitude dayside magnetopause. It will examine the contribution of high-latitude reconnection to the transport of mass, energy, and momentum from the solar wind to the magnetosphere. In particular, the investigation will focus on determining the role played by magnetic reconnection in the maintenance and the occasional thickening of the low latitude boundary layer (LLBL), as well as its role in providing plasma to the magnetotail plasma sheet during periods of northward interplanetary magnetic field (IMF). Magnetohydrodynamic (MHD) simulations and large-scale kinetic (LSK) calculations will be employed to follow fields and particles from the solar wind to the plasma sheet. Both in-situ measurements and ground observations will be used to initialize and validate the MHD and LSK simulations. Although the investigation will primarily focus on periods in which the shocked IMF reconnects with the geomagnetic field at high latitudes, cases of reconnection occurring at lower latitudes will also be investigated. A series of specific simulation studies based on the coordinated analysis of observations from the ACE, CLUSTER, GEOTAIL, POLAR, and WIND spacecraft, as well as ground-based data from the Super Dual Auroral Radar Network (SuperDARN) international network of high-frequency radars, have been identified for use in the investigation. The subjects of these studies include the large-scale structure and dynamics of the high-latitude dayside magnetosphere, the connectivity of the high-latitude region with the rest of the magnetosphere, and the large-scale kinetic processes involved in the structure and dynamics of the high-latitude region as well as the formation of the LLBL and the transport of solar wind plasma to the plasma sheet. The investigation will represent a significant contribution to the ultimate objective of the Geospace Environment Modeling program's Global Interaction (GI) campaign.
