[P-EM16] Heliosphere and Interplanetary Space

[PEM16-P06] On stochastic processes generating non-Gaussian particle distributions in the heliospheric plasma

*Yasuhiro Nariyuki¹, Yuseke Kosuga², Shogo Isayama³, Tohru Hada⁴ (1.Faculty of Education, University of Toyama, 2.Research Institute for Applied Mechanics, Kyushu University, 3.Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 4.International Research Center for Space and Planetary Environmental Science)

Keywords:heliospheric plasma, stochastic model, non-Gaussian distribution

Particle distributions in the heliospheric plasma usually have non-Gaussian characteristics[1]. Whereas the origin of each non-Gaussian distribution is diverse, stochastic modeling of particles is expected to be common in part. Since the stochastic process generating non-Gaussian particle distributions may not be unique, an adequate model should be selected. In this presentation, we revisit stochastic processes generating non-Gaussian particle distributions such as the kappa distribution[2]. By comparing the stochastic differential equations corresponding to Fokker-Planck equations in both Ito and Storatonovich sense[3], physical validity of models is discussed. We will also mention about stochastic models for non-Gaussian distribution observed in different systems such as laboratory plasmas.

[1]e.g., D. Verscharen, K. G. Klein, and B. A. Maruca, Living Rev. Sol. Phys. 16, 5 (2019). [2]e.g., G. Livadiotis and D. J. McComas, J. Geophys. Res., 114, A11105 (2009). [3]e.g., C. Gardiner, Stochastic methods, A handbook for the natural and social sciences. 4th ed. (Springer-Verlag Berlin Heidelberg, 2009).