This project will use a combination of spacecraft observations from the POLAR spacecraft (one of the missions that was part of NASA's International Solar Terrestrial Physics program) in conjunction with kinetic, 3-D simulations to examine the physical dynamics of collisionless magnetic reconnection. Earth's magnetopause provides an ideal laboratory for testing the validating the results that have been obtained by kinetic simulations of reconnection. Part of the research will involve the creation of a database of events from the POLAR spacecraft where the satellite crossed the reconnection separatrix and electron diffusion region. The spacecraft data will then be compared to the kinetic simulations. Specifically the project will examine three issues related to the physics of magnetic reconnection: (1) How the electron diffusion region evolves during the process, which leads to secondary islands and temporal fluctuations in the reconnection rate; (2) How the electron layers interact to generate turbulent reconnection; and (3) How the reconnection process leads to electric fields parallel to the ambient magnetic field and how these structures grow to macroscopic scales.
Magnetic reconnection plays a critical role in the process of converting energy stored in a magnetic field to kinetic energy of electrons and ions. In particular, collisionless reconnection is the primary mechanism by which energy is transferred from the solar wind into Earth's magnetosphere. Magnetic reconnection also plays a critical role in the generation of magnetic substorms and storms. These processes are important to our understanding of space weather. The database of reconnection events and the results from the simulations will both be made available to the space science community.