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.Comment: 10 pages, 5 figure