  As a main example for the superstatistics approach, we study a Brownian
particle moving in a d-dimensional inhomogeneous environment with macroscopic
temperature fluctuations. We discuss the average occupation time of the
particle in spatial cells with a given temperature. The Fokker-Planck equation
for this problem becomes a stochastic partial differential equation. We
illustrate our results using experimentally measured time series from
hydrodynamic turbulence.
