Bowen Trevor A, Chandran Benjamin D G, Squire Jonathan, Bale Stuart D, Duan Die, Klein Kristopher G, Larson Davin, Mallet Alfred, McManus Michael D, Meyrand Romain, Verniero Jaye L, Woodham Lloyd D
Space Sciences Laboratory, University of California, Berkeley, California 94720-7450, USA.
Department of Physics and Astronomy, University of New Hampshire, Durham, New Hampshire 03824, USA.
Phys Rev Lett. 2022 Oct 14;129(16):165101. doi: 10.1103/PhysRevLett.129.165101.
The dissipation of magnetized turbulence is an important paradigm for describing heating and energy transfer in astrophysical environments such as the solar corona and wind; however, the specific collisionless processes behind dissipation and heating remain relatively unconstrained by measurements. Remote sensing observations have suggested the presence of strong temperature anisotropy in the solar corona consistent with cyclotron resonant heating. In the solar wind, in situ magnetic field measurements reveal the presence of cyclotron waves, while measured ion velocity distribution functions have hinted at the active presence of cyclotron resonance. Here, we present Parker Solar Probe observations that connect the presence of ion-cyclotron waves directly to signatures of resonant damping in observed proton-velocity distributions using the framework of quasilinear theory. We show that the quasilinear evolution of the observed distribution functions should absorb the observed cyclotron wave population with a heating rate of 10^{-14} W/m^{3}, indicating significant heating of the solar wind.
磁化湍流的耗散是描述诸如日冕和太阳风等天体物理环境中的加热和能量转移的重要范例；然而，耗散和加热背后的具体无碰撞过程仍相对缺乏测量约束。遥感观测表明日冕中存在与回旋共振加热一致的强温度各向异性。在太阳风中，现场磁场测量揭示了回旋波的存在，而测量的离子速度分布函数暗示了回旋共振的活跃存在。在此，我们展示了帕克太阳探测器的观测结果，其利用准线性理论框架将离子回旋波的存在直接与观测到的质子速度分布中的共振阻尼特征联系起来。我们表明，观测到的分布函数的准线性演化应以10^{-14} W/m^{3}的加热率吸收观测到的回旋波群体，这表明太阳风存在显著加热。
