Magnetotail Configuration under Northward IMF Conditions

Abstract:

Due to the sparsity of space probes, it is still not clear on how the magnetic structure of the magnetotail looks like and how it evolves when the Interplanetary Magnetic Field (IMF) directs northward. We uses two different global magnetosphere MHD models hosted on NASA CCMC to simulate two northward IMF events and study the evolution of the magnetotail. Both models show that the magnetotail may form a structure that is composed of a dawnside tail lobe and a duskside tail lobe under northward IMF conditions with significant By, instead of a northern tail lobe and a southern tail lobe under southward IMF conditions. In this magnetic configuration, a tail lobe extends a domain from northern (or southern) cusp to southern (or northern) IMF. Such magnetic configuration suggests that magnetotail reconnection is possible to occur between the dawnside tail lobe and the duskside tail lobe under northward IMF conditions with significant By. We will show how the magnetotail evolves as the IMF clock angle changes, and how a tail reconnection is possible to occur under northward IMF conditions.