Matthaeus W H, Wan Minping, Servidio S, Greco A, Osman K T, Oughton S, Dmitruk P
Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA Dipartimento di Fisica, Università della Calabria, Arcavacata, Rende, Italy Dipartimento di Fisica e Astronomia, Università di Firenze, Firenze, Italy
Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA.
Philos Trans A Math Phys Eng Sci. 2015 May 13;373(2041). doi: 10.1098/rsta.2014.0154.
An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.
本文概述了空间和时间间歇性的重要特性，包括其在流体、磁流体和等离子体中出现的证据，以及对理解日球层等离子体的意义。空间间歇性通常与尖锐梯度和相干结构的形成有关。结构生成的基本物理原理是理想的，但当存在耗散时，它通常集中在强梯度区域。流体中空间间歇性的这一基本特征最近已被证明可延伸到动力学等离子体领域，在该领域中，耗散函数并非从第一原理得知。间歇性等离子体中产生的空间结构会影响耗散、加热以及带电粒子的输运和加速。时间间歇性可导致非常长的时间相关性或对稳态条件的延迟趋近，并且与反向级联或准反向级联系统有关，这可能对日球层预测有影响。
