A Systematic Look at the Temperature Contribution to the Dayside
Magnetopause Current
Abstract
Magnetopause diamagnetic currents arise from density and temperature
driven pressure gradients across the boundary layer. While theoretically
recognized, the temperature contributions to the magnetopause current
system have not yet been systematically studied. To bridge this gap, we
used a database of Magnetospheric Multiscale (MMS) magnetopause
crossings to analyze diamagnetic current densities and their
contributions across the dayside and flank magnetopause. Our results
indicate that the ion temperature gradient component makes up to 38% of
the ion diamagnetic current density along the magnetopause and typically
opposes the classical Chapman-Ferraro current direction, interfering
destructively with the density gradient component, thus lowering the
total diamagnetic current density. This effect is most pronounced on the
flank magnetopause. The electron diamagnetic current was found to be 5
to 16 times weaker than the ion diamagnetic current on average.