One of the factors, which affect the solar wind-magnetosphere interaction is an orientation of the interplanetary magnetic field (IMF). The rarely observed radial IMF results in a magnetopause location shift up to several Earth's radii different than predicted and can cause the specific magnetopause shape.
We present a statistical study from the years of 2009-2013 of magnetopause crossings which were observed by the THEMIS spacecraft. We analyze the differences between observed magnetopause positions and those which are predicted by the Shue et al. [1997] magnetopause model for a radial IMF.
We use the data (if available) from both L1 point and near-Earth solar wind monitors as a model input. Analysing our data set, we can conclude that under a long-lasting radial IMF, the magnetopause expands in all magnetic local times rather than creates a bullet-like shape.
A typical deviation between observed and predicted magnetopause locations is 0.8 RE.