【学术报告】
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报告题目：Nonlinear damping of Alfvén wave

报告人：赵金松 副研究员

报告人单位：中国科学院紫金山天文台

报告时间：2016年9月9日（周五）上午10:00-11:00

报告地点：Y12 会议室

报告语言：中文

报告摘要：

Here we report some recent progresses on the nonlinear damping of Alfvén wave caused by the decay instability. It finds that the scalar and vector nonlinear effects dominate the decay of the long-wavelength and short-wavelength Alfvén wave, respectively, in the decay instability of the Alfvén wave decayed into the Alfvén and slow waves. The scalar decay has both local and nonlocal decay property, which can excite the kinetic-scale Alfvén and slow waves by the MHD-scale Alfvén wave. The vector mechanism displays the local decay property, and its nonlinear excitation rate reaches the maximum as the perpendicular wavelength is of the order of the ion gyroradius scale.

We propose a vector Alfvén wave decay as a feasible mechanism for the observed Alfvén wave damping in the solar corona below 1.5 solar radii. Contrary to the extensively studied scalar decay, the vector decay does not depend on the wave frequency and can be efficient for low-frequency coronal Alfvén waves. We show that the vector decay is much stronger than the scalar decay and can provide the observed damping of 0.01 Hz coronal Alfvén waves with perpendicular wavelengths of ~10 Mkm or less. 

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抚仙湖太阳观测与研究基地

云南天文台学术委会　　

邀请方联系人：闫晓理 13577019309

9月8日