The Effect on Geospace Environment of Small-scale Magnetic Flux Ropes in the Solar Wind

Small-scale magnetic flux ropes (SMFRs), a bundle of twisted field lines, are frequently observed from multiple spacecraft in the solar wind over a wide range of region from 0.29 to 8 au [Chen & Hu, 2020]. Since it is widely known that rotating magnetic field structure is favorable for build-up, release and transport of free energy, there is a significant point to look into transient energy transfer near the boundary between SMFRs and the Earth’s magnetosphere. However, their interaction has not yet been widely studied even if it may play an important role to energy transfer from the solar wind to Earth’s magnetosphere. As our pilot study found that there is a statistically similar trend of occurrence rates of SMFRs and substorms, we perform a statistical analysis by comparing between SMFRs and geospace response in terms of duration, magnitude, scale size, and orientation of SMFRs. We also use particle data from MMS to investigate geomagnetic activity and plasma characteristics both outside and within the Earth’s magnetosphere during passages of SMFRs. We here propose a comprehensive observational and technical effort to understand the transport of small-scale transient from the solar wind to the Earth’s environment. We target key candidates for such events, including SMFRs, substorms, and in-situ observations obtained from magnetospheric missions.