Energy EXchange At the Magnetopause (EEXAM)

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The Earth’s magnetopause is an electric current layer separating the magnetospheric and shocked solar wind plasmas and their magnetic topologies, often detectable by an abrupt change in local plasma and magnetic field conditions. Understanding the transferred energy and where and under which local and global conditions the most significant energy transfer occurs is important for predicting magnetospheric disturbances. Local processes at the boundary, coupled with the magnetospheric dynamics, the transferred energy powering space weather impacts in space and on the ground. For the first time, this project will extensively use in-situ observations to determine the statistics of the direct energy transfer through the magnetopause and construct an assessment of the importance of the boundary motion, which results in magnetospheric energy acquisitions and forfeitures. The work includes an inclusive research experience component for undergraduate students, which will contribute to educating the next generation scientists. A large statistical set of over 4,000 magnetopause crossings of the Magnetospheric Multiscale mission is employed to resolve the local energy exchange at the low-latitude dayside magnetopause. The conducted work analyzes multi-spacecraft electromagnetic field and plasma measurements to evaluate the magnetopause energetics, including the exchanged energy (entry vs. exit), its content (electromagnetic vs. hydrodynamic), and energy conversion rate at the boundary, as well as the dependence on the upstream solar wind conditions and magnetospheric state. The project will assess how the interplay between the current state of the system and the external driver reflects the outer boundary dynamics and provide the first spatial mapping of the energy transfer and its content at the low-latitude dayside magnetopause. The effects of the magnetopause motion due to varying solar wind flow and magnetospheric reconfigurations have yet to be accounted for in observational analyses. This project will evaluate the contributions of magnetospheric compressions and expansions to the system energy content and how the energy exchange processes are modulated due to the boundary motion. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.