标题：A two-fluid modeling of kinetic Alfven wave turbulence
作者：Kumar, Sanjay; Dwivedi, Navin Kumar; Sharma, R. P.; Moon, Y. -J.
作者机构：[Kumar, Sanjay; Moon, Y. -J.] Kyung Hee Univ, Sch Space Res, Yongin 446701, Gyeonggi Do, South Korea.; [Kumar, Sanjay] Shandong Univ, Inst Space Sci 更多
通讯作者：Kumar, S;Kumar, S
通讯作者地址：[Kumar, S]Kyung Hee Univ, Sch Space Res, Yongin 446701, Gyeonggi Do, South Korea;[Kumar, S]Shandong Univ, Inst Space Sci, Shandong Prov Key Lab Opt As 更多
来源：ASTROPHYSICS AND SPACE SCIENCE
关键词：Plasma turbulence; Solar wind; Nonlinear waves; Kinetic Alfven waves;; Magnetic field spectra
摘要：We present an analytical model to explore the magnetic field turbulent spectrum by coupled high-frequency kinetic Alfven wave (KAW) and slow mode of Alfven wave (AW). The spectrum is computed as a realization of energy cascades from larger to smaller scales for a specific case of solar wind plasma at 1 AU. A two-fluid technique is implemented for the derivation of model equations leading two wave modes. These coupled, nonlinear equations are solved numerically. The nonlinearity in the system arises due to nonlinear ponderomotive force, which is believed to be responsible for the wave localization and magnetic islands formation. The numerical results show that the magnetic islands grow with time and attain a quasi-steady state after the modulation instability is saturated. The magnetic field spectrum and associated spectral indices are computed near the time of saturation of instability. The simulated spectrum in dispersion region follows a power-law with an index of -2.5. The steeper spectrum could be attributed as energy transfer from larger to smaller scales and helps to study turbulence in solar wind. The magnetic field spectrum and spectral index show a good agreement with the observation of solar wind turbulent spectra.