Propagation of small size magnetic holes in the magnetospheric plasma sheet

摘要: Magnetic holes (MHs), characteristic structures where the magnetic field magnitude decreases significantly, have been frequently observed in space plasmas. Particularly, small size (SSMHs) which scale is less than or close to proton gyroradius are recently detected magnetospheric plasma sheet. In this study of Cluster observations, by timing method, minimum directional difference (MDD) and spatiotemporal (STD) we obtain propagation velocity SSMHs flow frame. Furthermore, based on electron magnetohydrodynamics (EMHD) theory calculate velocity, width, depth solitary wave compare it SSMH observations. The result shows a good accord between observation.