• Login
     
    View Item 
    •   ORFEO Home
    • Royal Belgian Institute for Space Aeronomy
    • BIRA-IASB publications
    • View Item
    •   ORFEO Home
    • Royal Belgian Institute for Space Aeronomy
    • BIRA-IASB publications
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Implication of kinetic Alfvén waves to magnetic field turbulence spectra: Earth's magnetosheath

    Thumbnail
    View/Open
    Dwivedi(2019a).pdf (2.158Mb)
    Authors
    Dwivedi, N.K.
    Kumar, S.
    Kovacs, P.
    Yordanova, E.
    Echim, M.
    Sharma, R.P.
    Khodachenko, M.L.
    Sasunov, Y.
    Show allShow less
    Discipline
    Physical sciences
    Subject
    Turbulence
    Magnetic field spectra
    Spectral slope
    Kinetic Alfvén wave
    Nonlinearity
    Audience
    Scientific
    Date
    2019
    Metadata
    Show full item record
    Description
    In the present paper, we investigate the power-law behaviour of the magnetic field spectra in the Earth’s magnetosheath region using Cluster spacecraft data under solar minimum condition. The power spectral density of the magnetic field data and spectral slopes at various frequencies are analysed. Propagation angle, θkB, and compressibility, R∥, are used to test the nature of turbulent fluctuations. The magnetic field spectra have the spectral slopes, α, between −1.5 to 0 down to spatial scales of 20ρi (where ρi is ion gyroradius), and show clear evidence of a transition to steeper spectra for small scales with a second power-law, having α between −2.6 to −1.8. At low frequencies, fsc<0.3fci (where fci is ion gyro-frequency), θkB∼90∘ to the mean magnetic field, B0, and R∥ shows a broad distribution, 0.1≤R∥≤0.9. On the other hand at fsc>10fci, θkB exhibits a broad range, 30∘≤θkB≤90∘, while R∥ has a small variation: 0.2≤R∥≤0.5. We conjecture that at high frequencies, the perpendicularly propagating Alfvén waves could partly explain the statistical analysis of spectra. To support our prediction of kinetic Alfvén wave dominated spectral slope behaviour at high frequency, we also present a theoretical model and simulate the magnetic field turbulence spectra due to nonlinear evolution of kinetic Alfvén waves. The present study also shows the analogy between the observational and simulated spectra.
    Citation
    Dwivedi, N.K.; Kumar, S.; Kovacs, P.; Yordanova, E.; Echim, M.; Sharma, R.P.; Khodachenko, M.L.; Sasunov, Y. (2019). Implication of kinetic Alfvén waves to magnetic field turbulence spectra: Earth's magnetosheath. , Astrophysics and Space Science, Vol. 364, Issue 6, A101, DOI: 10.1007/s10509-019-3592-2.
    Identifiers
    uri: https://orfeo.belnet.be/handle/internal/7294
    doi: http://dx.doi.org/10.1007/s10509-019-3592-2
    Type
    Article
    Peer-Review
    Yes
    Language
    eng
    Links
    NewsHelpdeskBELSPO OA Policy

    Browse

    All of ORFEOCommunities & CollectionsBy Issue DateAuthorsTitlesDisciplinesThis CollectionBy Issue DateAuthorsTitlesDisciplines
     

    DSpace software copyright © 2002-2016  DuraSpace
    Send Feedback | Cookie Information
    Theme by 
    Atmire NV