The context of the present work is the one of planetary plasma environments. I show how, by analysis of in-situ observations combined to numerical simulations and statistical processing, consistent scenarios of the evolution of these environments can emerge. I thus address three distinct areas of applications. Firstly, as a result of my thesis work, a model of particle acceleration in magnetized and strongly inhomogeneous plasmas is presented with an application to terrestrial auroral regions. I then show various analytical and numerical approaches to refine our understanding of instrumental measurements of low energy plasmas. Finally, I discuss recent works on the dynamics of planetary magnetosheaths from the analysis of fluctuations characteristic of this environment, the mirror modes. I conclude by presenting the perspectives of these works as well as those offered by the tools developed in recent years at the Plasma Physics Data Centre.
