Universal Probability Distribution Function for Bursty Transport in Plasma Turbulence

TL;DR

This paper introduces a universal probability distribution function derived from a stochastic model that accurately describes bursty transport phenomena in plasma turbulence and other convection-driven systems, capturing their universal statistical features.

Contribution

The paper presents a new stochastic univariate model and probability distribution function that universally characterizes bursty transport in plasma turbulence and similar systems.

Findings

The model reproduces the universal distribution of density fluctuations in plasma edge.

It captures the scaling relationship between skewness and kurtosis.

Similar statistical features are observed in other convection-driven physical systems.

Abstract

Bursty transport phenomena associated with convective motion present universal statistical characteristics among different physical systems. In this letter, a stochastic univariate model and the associated probability distribution function for the description of bursty transport in plasma turbulence is presented. The proposed stochastic process recovers the universal distribution of density fluctuations observed in plasma edge of several magnetic confinement devices and the remarkable scaling between their skewness $S$ and kurtosis $K$. Similar statistical characteristics of variabilities have been also observed in other physical systems that are characterized by convection such as the X-ray fluctuations emitted by the Cygnus X-1 accretion disc plasmas and the sea surface temperature fluctuations.