Quantifying wave-particle interactions in ion temperature anisotropy instabilities

In collisionless plasmas such as the solar wind, the particle velocity distributions can be shaped by various wave-particle interactions, which lead to effective energy transfer between electromagnetic fields and particles. The commonly-observed quasi-monochromic waves by in-situ satellites are widely believed to be generated by plasma instabilities via wave-particle interactions. Thus, how to quantify the role(s) of wave-particle interactions in plasma instabilities is a fundamental problem in the space plasma community. Recently, we developed a theoretical method quantifying both resonant and nonresonant wave-particle interactions, and we performed the comprehensive analyses on ion temperature anisotropy instabilities in the solar wind. This report will introduce new findings.