| Summary: | 碩士 === 國立中央大學 === 太空科學研究所 === 91 ===
Magnetopause plays an important role in the interaction between the solar wind and earth’s magnetosphere. Conventionally the magnetopause current layer is described by two simple one-dimensional magnetohydrodynamic (MHD) models that are tangential discontinuity (TD) and rotational discontinuity (RD) associated with the closed and open models of the magnetosphere. Hau and Sonnerup [1999] have developed a new technique to reconstruct the 2D tangential-discontinuity like magnetopause structure by using the single satellite data obtained during magnetopause crossings. These authors found that a series of pearl like magnetic islands are embedded within the magnetopause that is presumably caused by the tearing mode instability. Due to the physics constraints and hypotheses required to reconstruct such self-consistent plasma structures, only a few of these cases have been found to date. The purpose of this paper is to seek for further evidence of magnetic island structure at the magnetopause. We have surveyed the two-year AMPTE/IRM plasma and magnetic field data during the magnetopause crossings based on the analysis methods of Minimum Variance Analysis (MVA), Minimization of Faraday Residue (MFR), DeHoffmann-Teller Velocity Analysis, and Analytical Error Estimate as well as Bootstrap Method for MVA. Using these analysis results along with the reconstruction method of Hau and Sonnerup [1999], we have identified two events that show a series of magnetic island structure within the magnetopause with island width of about 500 km. These two events occur at the dawn and dusk sides of the magnetopause flank and are convecting tailward with high speed of ~200 km/s.
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