Physics
Scientific paper
May 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agusmsh21c..03d&link_type=abstract
American Geophysical Union, Spring Meeting 2002, abstract #SH21C-03
Physics
7509 Corona, 7511 Coronal Holes, 7843 Numerical Simulation Studies, 7863 Turbulence, 2149 Mhd Waves And Turbulence
Scientific paper
In order to sustain incompressible MHD turbulence fluctuations with opposite cross helicity signs are required. In an open region permeated by a strong background magnetic field this means that both upward and downward parallel propagating Alfven waves are needed to interact and produce a nonlinear energy transfer to small perpendicular (to the mean field) length scales. This provides an efficient heating mechanism mediated by the MHD turbulence. The questions that raise are: How ``efficient'' is this mechanism ? Which are the relevant parameters that control the turbulence sustainment and heating efficiency ? By doing numerical simulations of the RMHD equations in an open box with inhomogeneous background density we first show that even a very low amount of downward fluctuations (less than 10% of the upward fluctuations) can provide a reasonable level of turbulence, and heating efficiency. We proceed then to study the effect of the externally imposed timescales (boundary forcing timescales and Alfven wave crossing time), their relationship with the fluctuations nonlinear timescales and how their modification can increase or decrease the heating efficiency. The effect of those external timescales on the energy cascade to small perpendicular length scales is discussed. This model is relevant to the problem of heating in coronal holes but its implications for the general theory of MHD turbulence are also interesting.
Dmitruk Pablo
Matthaeus William H.
No associations
LandOfFree
Sustainment and Heating Efficiency of Magnetohydrodynamic Turbulence in Open Field Line Coronal Regions: the Influence of the External Timescales does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Sustainment and Heating Efficiency of Magnetohydrodynamic Turbulence in Open Field Line Coronal Regions: the Influence of the External Timescales, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sustainment and Heating Efficiency of Magnetohydrodynamic Turbulence in Open Field Line Coronal Regions: the Influence of the External Timescales will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1723174