Residual energy in MHD turbulence and in the solar wind

被引:15
作者
Boldyrev, Stanislav [1 ]
Perez, Jean Carlos [1 ]
Zhdankin, Vladimir [1 ]
机构
[1] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
来源
PHYSICS OF THE HELIOSPHERE: A 10 YEAR RETROSPECTIVE | 2012年 / 1436卷
关键词
Alfven waves; Turbulence; Solar Wind; ALFVENIC TURBULENCE; SPECTRA;
D O I
10.1063/1.4723584
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Recent observations indicate that kinetic and magnetic energies are not in equipartition in the solar wind turbulence. Rather, magnetic fluctuations are more energetic and have somewhat steeper energy spectrum compared to the velocity fluctuations. This leads to the presence of the so-called residual energy E-r = E-v - E-b in the inertial interval of turbulence. This puzzling effect is addressed in the present paper in the framework of weak turbulence theory. Using a simple model of weakly colliding Alfven waves, we demonstrate that the kinetic-magnetic equipartition indeed gets broken as a result of nonlinear interaction of Alfven waves. We establish that magnetic energy is indeed generated more efficiently as a result of these interactions, which proposes an explanation for the solar wind observations.
引用
收藏
页码:18 / 23
页数:6
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