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Article
A Statistical Study of Magnetic Field Fluctuations in the Dayside Magnetosheath and Their Dependence on Upstream Solar Wind Conditions
Journal of Geophysical Research: Space Physics
  • A. P. Dimmock, Aalto University
  • K. Nykyri, Embry-Riddle Aeronautical University
  • T. I. Pulkkinen, Aalto University
Submitting Campus
Daytona Beach
Department
Physical Sciences
Document Type
Article
Publication/Presentation Date
8-1-2014
Abstract/Description

The magnetosheath functions as a natural interface connecting the interplanetary and magnetospheric plasma. Since the magnetosheath houses the shocked solar wind, it is populated with abundant magnetic field turbulence which are generated both locally and externally. Although the steady state magnetosheath is to date relatively well understood, the same cannot be said of transient magnetic perturbations due to their kinetic nature and often complex and numerous generation mechanisms. The current manuscript presents a statistical study of magnetic field fluctuations in the dayside magnetosheath as a function of upstream solar wind conditions. We concentrate on the ambient higher-frequency fluctuations in the range of 0.1 Hz → 2 Hz. We show evidence that the dawn (quasi-parallel) flank is visibly prone to higher-amplitude magnetic perturbations compared to the dusk (quasi-perpendicular) region. Our statistical data also suggest that the magnitude of turbulence can be visibly enhanced close to the magnetopause during periods of southward interplanetary magnetic field orientations. Faster (> 400 km s−1) solar wind velocities also appear to drive higher-amplitude perturbations compared to slower speeds. The spatial distribution also suggests some dependence on the magnetic pileup region at the subsolar magnetopause.

DOI
https://doi.org/10.1002/2014JA020009
Publisher
American Geophysical Union
Grant or Award Name
NSF grant 0847120, Academy of Finland grant 267073/2013
Citation Information
Dimmock, A. P., K. Nykyri, and T. I. Pulkkinen (2014), A statistical study of magnetic field fluctuations in the dayside magnetosheath and their dependence on upstream solar wind conditions, J. Geophys. Res. Space Physics, 119, 6231–6248, doi:10.1002/2014JA020009