发表机构
Sikkim University; Netaji Subhas University of Technology（锡金大学; 内塔吉·苏巴斯技术大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用Wind卫星数据，发现慢太阳风中阿尔文性水平与平行模边际稳定性接近度相关，阿尔文性慢风波动振幅更低，更接近稳定性阈值，但因果关系未确定。
AI 中文摘要
太阳风中的质子温度各向异性受到压力各向异性驱动的动力学不稳定性阈值的约束，等离子体从这些阈值回退的距离被认为通过波动各向异性效应由压缩性波动调节。我们测试了在慢太阳风中阿尔文性水平是否与该距离相关。利用五年的Wind/SWE双麦克斯韦质子测量数据（2004--2008），我们根据归一化交叉螺旋度和剩余能量将慢风区间分为阿尔文性和非阿尔文性群体。我们比较了它们的磁压缩分数和归一化压缩振幅，并使用Vlasov色散求解器在扫描的平行波数上计算最大增长率$\gamma_{\parallel,\max}$，测量它们在平行质子β和温度各向异性平面中与边际稳定性的接近程度。在匹配的低平行β下，阿尔文性慢风具有较低的归一化场强波动振幅，并且比非阿尔文性慢风更频繁地达到平行模边际稳定性标准。这种关联与阿尔文性慢风中较弱的波动各向异性效应一致，但并未建立因果关系。
英文摘要
The proton temperature anisotropy in the solar wind is bounded by the thresholds of pressure-anisotropy-driven kinetic instabilities, and the distance at which the plasma settles from these thresholds is thought to be regulated by compressive fluctuations through the fluctuating anisotropy effect. We test whether the level of Alfvénicity is associated with this distance in the slow solar wind. Using five years of Wind/SWE bi-Maxwellian proton measurements (2004--2008), we separate slow-wind intervals into Alfvénic and non-Alfvénic populations on the basis of normalized cross helicity and residual energy. We compare their magnetic compressive fraction and normalized compressive amplitude, and measure their proximity to marginal stability in the plane of parallel proton beta and temperature anisotropy using the maximum growth rate over the scanned parallel wavenumbers, $γ_{\parallel,\max}$, from a Vlasov dispersion solver. At low matched parallel beta, the Alfvénic slow wind has lower normalized field-strength fluctuation amplitude and reaches the parallel-mode marginal-stability criterion more often than the non-Alfvénic slow wind. This association is consistent with a weaker fluctuating-anisotropy effect in the Alfvénic slow wind, but does not establish a causal relation.
Comments14 pages, 7 figures, 3 tables. Accepted for publication in Journal of Subatomic Particles and Cosmology
