Abstract Details
| Name: Mahendra Verma Affiliation: IIT Kanpur Conference ID: ASI2017_1163 Title : How MHD Turbulence theories can help understand solar wind and solar magnetic field. Authors and Co-Authors : Mahendra Verma, Physics Department, IIT Kanpur Abstract Type : Oral Abstract Category : Sun and the Solar System Abstract : Most astrophysical states are described by magnetohydrodynamics (MHD) turbulence. The physics of MHD turbulence is not fully understood. According to Kraichnan and Iroshinokov, the turbulence phenomenology differs significantly from hydrodynamic turbulence due to the mean magnetic field, and the spectrum is proportional to $B_0^{½} k^{-3/2}$. However, Verma [1] showed that the “effective mean magnetic field†is wavenumber dependent ($B_0 \sim k^{-⅓}$), which leads to $k^{-5/3}$ spectrum, as is observed in the solar wind. The above theory can be used used to estimate the turbulent dissipation in the solar wind and solar corona [2,3]. The turbulence however is suppressed by the mean magnetic field that should affect the dissipation rate. These aspects need further investigation. These theories also help understand the magnetic field generation or dynamo. The growth of the large-scale magnetic field occurs due to the energy supply or flux from the large-scale velocity field to large-scale magnetic field [3]. References: [1] M. K. Verma, Mean magnetic field renormalization and Kolmogorov's energy spectrum in magnetohydrodynamic turbulence, Phys. Plasmas, 6, 1455 (1999). [2] M. K. Verma, D. A. Roberts, and M. L. Goldstein, Turbulent heating and temperature evolution in the solar wind plasma, J. of Geophys.Res., 100, 19839 (1995). [3] M. K. Verma, Statistical theory of magnetohydrodynamic turbulence: recent results, Phys. Rep., 401, 229-380 (2004). |