Observations of large‐amplitude, parallel, electrostatic waves associated with the Kelvin‐Helmholtz instability by the magnetospheric multiscale mission

详细信息    查看全文

• 作者：F. D. Wilder ; R. E. Ergun ; S. J. Schwartz ; D. L. Newman ; S. Eriksson ; J. E. Stawarz ; M. V. Goldman ; K. A. Goodrich ; D. J. Gershman ; D. M. Malaspina ; et al
• 刊名：Geophysical Research Letters
• 出版年：2016
• 出版时间：16 September 2016
• 年：2016
• 卷：43
• 期：17
• 页码：8859-8866
• 全文大小：833.2KB
• ISSN：1944-8007

文摘

On 8 September 2015, the four Magnetospheric Multiscale spacecraft encountered a Kelvin-Helmholtz unstable magnetopause near the dusk flank. The spacecraft observed periodic compressed current sheets, between which the plasma was turbulent. We present observations of large-amplitude (up to 100 mV/m) oscillations in the electric field. Because these oscillations are purely parallel to the background magnetic field, electrostatic, and below the ion plasma frequency, they are likely to be ion acoustic-like waves. These waves are observed in a turbulent plasma where multiple particle populations are intermittently mixed, including cold electrons with energies less than 10 eV. Stability analysis suggests a cold electron component is necessary for wave growth.