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

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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.