20 Years of Cluster Observations: The Magnetopause

Abstract

<p>The terrestrial magnetopause forms the boundary between the solar wind plasma with its embedded interplanetary magnetic field on one side, and the terrestrial magnetosphere, dominated by Earth's dipole field, on the other side. It is therefore a key region for the transfer of mass, momentum, and energy from the solar wind to the magnetosphere. The Cluster mission, comprising a constellation of four spacecraft flying in formation was launched more than 20 years ago to study boundaries in space. During its lifetime, Cluster has provided a wealth of new knowledge about the magnetopause. In this presentation, we give an overview of Cluster-based studies of this boundary, and highlight a selection of interesting results. </p>

Magnetopause location modeling using machine learning: inaccuracy due to solar wind parameter propagation

“…This boundary takes a form of an electric current sheet with a paraboloid shape. Its subsolar distance is typically 10 to 12 Earth radii (R E , R E ≈ 6371km) (Haaland et al, 2021). The shape and location of the magnetopause are not constant; they vary according to the upstream solar wind conditions and the internal state of the magnetosphere.…”

Measurements of the Net Charge Density of Space Plasmas

“…Cluster mission has first achieved the four‐point measurements on the electric field in space (Escoubet et al., 2001), with which the electric field structure of the magnetopause boundary layer has been revealed (Haaland et al., 2021; Paschmann et al., 2005; and references therein). The Magnetospheric MultiScale (MMS) constellation (Burch et al., 2016) can measure the three‐dimensional electric field vector at four locations in space so as to obtain the linear gradient of the electric field.…”