摘要： A statistical study of the structure of Earth's magnetopause is carried out by analyzing two‐year AMPTE/IRM plasma and magnetic field data. The analyses are based on the minimum variance analysis (MVA), the deHoffmann‐Teller (HT) frame analysis and the Walén relation. A total of 328 magnetopause crossings are identified and error estimates associated with MVA and HT frame analyses are performed for each case. In 142 out of 328 events both MVA and HT frame analyses yield high quality results which are classified as either tangential‐discontinuity (TD) or rotational‐discontinuity (RD) structures based only on the Walén relation: Events withSWA ≤ 0.4 (SWA ≥ 0.5) are classified as TD (RD), and rest (with 0.4 < SWA < 0.5) is classified as “uncertain,” where SWA refers to the Walén slope. With this criterion, 84% of 142 events are TDs, 12% are RDs, and 4% are uncertain events. There are a large portion of TD events which exhibit a finite normal magnetic field component Bnbut have insignificant flow as compared to the Alfvén velocity in the HT frame. Two‐dimensional Grad‐Shafranov reconstruction of forty selected TD and RD events show that single or multiple X‐line accompanied with magnetic islands are common feature of magnetopause current. A survey plot of the HT velocity associated with TD structures projected onto the magnetopause shows that the flow is diverted at the subsolar point and accelerated toward the dawn and dusk flanks. Key Points This paper presents the first systematic study of magnetopause structure The physics of solar wind‐magnetosphere interaction is clearly revealed The study shows that the ratio of slow to fast reconnections is 7:1 其他題名： J. Geophys. Res 出版者： Washington, DC: Blackwell Publishing Ltd 出版日期： 2012-08 出處： Journal of Geophysical Research: Space Physics, 2012-08, Vol.117 (A8), p.n/a 資源來源： Wiley Online Library Journals 版權： 2012. American Geophysical Union. All Rights Reserved. 版權： 2015 INIST-CNRS 識別號： ISSN: 0148-0227 識別號： ISSN: 2169-9380 識別號： EISSN: 2156-2202 識別號： EISSN: 2169-9402 識別號： DOI: 10.1029/2011JA017155
