Massive Multi-Mission Statistical Study and Analytical Modeling of the Earth's Magnetopause: 4. On the Near-Cusp Magnetopause Indentation

摘要

The shape and location of the magnetopause current sheet in the near-cusp region is still a debated question. Over time, several observations led to contradictory conclusions regarding the presence of an indentation of the magnetopause in that region. As a result several empirical models consider the surface is indented in that region, while some others do not. To tackle this issue, we fit a total of 17,230 magnetopause crossings to various indented and non-indented analytical models. The results show that while all models describe the magnetopause position and shape equivalently far from the cusp region, the non-indented version over-estimate the radial position of the near-cusp magnetopause. Among indented models, we show that the one designed from non-linearmagneto hydrodynamic simulations fits well the near-cusp magnetopause location, while the other underestimate its position probably because their design was possibly based on magnetopause crossing catalogs that contain cusp inner boundary crossings.