Understanding the sun is important for assessing & predicting it's effect on our climate & potential catastrophes from solar storms

与流体紊流类似，完全电离磁化气体中的紊流是高度非线性的。磁场和带电粒子的存在大大增加了对等离子体湍流的理解。由于两个因素，空间等离子体中的湍流研究更具挑战性：1空间等离子体通常具有较大的流动速度。这类等离子体的取样是困难的，而且常常限于单个卫星观测。因此，当多卫星数据可用时，将对空间等离子体物理学的研究具有很高的价值。由于大多数天体物理物质都处于等离子体状态，因此等离子体湍流研究的天体物理意义是显而易见的。该项目将使用多航天器数据分析工具，如k滤波和相位差技术，在（或亚）离子惯性和旋转尺度上研究太阳风和空间等离子体湍流的特性。这两种技术将是互补的。虽然k滤波技术（在我们小组已经开发和实施）能够在离子惯性和旋转尺度上提供等离子体湍流的统计平均信息，但从该技术获得的结果缺乏在上述尺度上引起等离子体湍流的少数等离子体干扰因素的重要信息。然而，相位差技术（我们小组正在开发）能够提供单个波包的详细信息，包括波包传播的方向，这些波包的标度规律和波数空间各向异性。这将为研究太阳风湍流提供新的机会，因为对大量波包的处理将揭示具有统计意义的等离子体湍流成分。本项目旨在揭示太阳风等离子体亚离子尺度的阿尔芬波湍流、动力学快波和慢波湍流的意义。

Similar to fluid turbulence, turbulence in fully ionzed magnetized gases is highly non-linear. The existence of magnetic field and charged particles make the understanding of plasma turbulence substantially more difficult. Turbulence in space plasmas is even more challenging to study due to two factors: 1 space plasmas are often with large flow speeds. 2: the sampling of such plasmas is difficult and often limited to single satellite observation. Hence multi-satellite data, when available, will be highly valuable for the study of space plasma physics. Since most astrophysical materials are in plasma state, the astrophysical significance of plasma turbulence study is obvious. The project will use multi-spacecraft data analysis tools such as k-filtering and phase-differencing techniques to investigate the property of solar wind and space plasma turbulence at (or sub-) ion inertial and gyration scales. The two techniques will be complimentary to each other. While the k-filtering technique (already developed and conducted in our group) is able to provide statistically averaged information of plasma turbulence at ion inertial and gyration scales, results obtained from the technique lack important information of the minority plasma disturbance contributors to the plasma turbulence at the said scales. The phase-differencing technique (which is under development in our group) however is capable of providing the detailed information of individual wave packets including the direction that wave packets are propagating, scaling laws of these wave packets and the wave number space anisotropy. This will offer new opportunities for investigating solar wind turbulence since the treatment of large number of wave packets will reveal ingredients of plasma turbulence with statistical significance. The project aims to reveal the significance of Alfven wave turbulence, kinetic fast and slow wave turbulence at sub-ion scales in the solar wind plasma.