Notice:

Strategies for Determining the Cascade Rate in MHD Turbulence: Isotropy, Anisotropy, and Spacecraft Sampling
Author  Wang, Yanwen; Chhiber, Rohit; Adhikari, Subash; Yang, Yan; Bandyopadhyay, Riddhi; Shay, Michael; Oughton, Sean; Matthaeus, William; Cuesta, Manuel; 
Keywords  Parker Data Used; interplanetary turbulence; Space plasmas; Plasma physics; Magnetohydrodynamics; Magnetohydrodynamical simulations; 830; 1544; 2089; 1964; 1966; Physics  Space Physics; Physics  Fluid Dynamics; Physics  Plasma Physics 
Abstract  Exact laws for evaluating cascade rates, tracing back to the Kolmogorov 4/5 law, have been extended to many systems of interest including magnetohydrodynamics (MHD), and compressible flows of the magnetofluid and ordinary fluid types. It is understood that implementations may be limited by the quantity of available data and by the lack of turbulence symmetry. Assessment of the accuracy and feasibility of such thirdorder (or Yaglom) relations is most effectively accomplished by examining the von K\ arm\ anHowarth equation in increment form, a framework from which the thirdorder laws are derived as asymptotic approximations. Using this approach, we examine the context of thirdorder laws for incompressible MHD in some detail. The simplest versions rely on the assumption of isotropy and the presence of a welldefined inertial range, while related procedures generalize the same idea to arbitrary rotational symmetries. Conditions for obtaining correct and accurate values of the dissipation rate from these laws based on several sampling and fitting strategies are investigated using results from simulations. The questions we address are of particular relevance to sampling of solar wind turbulence by one or more spacecraft. 
Year of Publication  2022 
Journal  \apj 
Volume  937 
Number of Pages  76 
Section  
Date Published  oct 
ISBN  
URL  
DOI  10.3847/15384357/ac8f90 