High Temporal and Spatial Resolution Measurements of the Earth’s Magnetopause: Fields, Currents, Forces and Topology Revealed

Russell, Christopher

High Temporal and Spatial Resolution Measurements of the Earth’s Magnetopause: Fields, Currents, Forces and Topology Revealed

Thursday, 13 July 2017: 13:30

Furong Room (Cynn Hotel)

Christopher T Russell¹, Robert J Strangeway¹, Cong Zhao¹, Brian J Anderson², Wolfgang Baumjohann³, Kenneth R Bromund⁴, David Fischer³, James A Slavin⁵, Larry Kepko^4,6, Guan Le⁴, Werner Magnes³, Rumi Nakamura³, Roy B Torbert⁶, William R Paterson⁴, Thomas Earle Moore⁴, Barbara L Giles⁴, Stephen A Fuselier⁷ and James Burch⁷, (1)University of California Los Angeles, Earth, Planetary, and Space Sciences, Los Angeles, CA, United States, (2)Johns Hopkins University, Baltimore, MD, United States, (3)Space Research Institute, Austrian Academy of Sciences, Graz, Austria, (4)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (5)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (6)University of New Hampshire Main Campus, Durham, NH, United States, (7)Southwest Research Institute, San Antonio, TX, United States

Abstract:

The magnetopause is strongly influenced by properties of the flowing plasma that it deflects. The Magnetospheric Multiscale Mission has enabled this interaction to be probed in intimate detail. We combine the magnetic measurements of the four spacecraft to demonstrate how the magnetic forces affect the boundary between the shocked solar wind and the Earth’s magnetic field. We compare these forces with the plasma pressure, confirming the accurate inter-calibration of the plasma and magnetic forces but draw attention to the trade-off between spatial resolution and accuracy of the gradient measurements so governed by the spacecraft separation. We use the electron distribution function measurements to examine the topology of the magnetic field. Small pockets of low magnetic field strength, small radius of curvature magnetic field lines and high electric current mark the electron diffusion region.