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| INSTITUTET FÖR RYMDFYSIK | UPPSALA |
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| Swedish Institute of Space Physics | (59°50.272′N, 17°38.786′E) |
Student project, advanced level (10c)/Studentprojekt, avancerad nivå (10hp)
Analysis of Magnetic Field and Electron Density Fluctuations in the Sheath of CMEs
Student: Karan Pal, Uppsala UniversitySupervisor: Emiliya Yordanova
Period: autumn 2021
Project
The subject of this project is the investigation of the sheath region of Interplanetary Coronal Mass Ejections (ICMEs). The region between the shock wave produced by the Coronal Mass Ejections (CMEs) when it is sufficiently fast and the beginning of magnetic structure of the CME is known as the sheath region of ICMEs. Magnetic field and electron density data from this region have been used in this report. The measurements used were provided by the Solar Orbiter (SolO) joint mission by NASA and ESA. To understand the fluctuations in the magnetic field and plasma density in the sheath region of CME, the Partial Variance of Increments (PVI) method has been used.It is found from this project that the CME sheaths resemble the turbulence of the solar wind. The power spectra follow the Kolmogorov or Iroshnikov-Kraichnan scaling in the inertial range. In the high frequency regime, the spectral law is characterized by dissipative process in general. This implies that the solar wind turbulence captured and confined in the sheath has not been completely modified by the propagating CME. Also, the correlation between the PVI B (PVI of magnetic field) and PVI Ne (PVI of electron density) was found to be weak for smaller scales and there is no correlation for the larger scales in CME sheath region.
Results
![[SoHO]](cme.jpg)
Coronal mass ejections are large eruptions originating in the solar corona, causing large perturbations in the solar wind.