A lagrangian dispersion model with a stochastic equation for the temperature fluctuations

The hybrid Lagrangian stochastic algorithm for buoyant plume rise from an isolated source described by Bisignano and Devenish (2015) is introduced into the Lagrangian dispersion model SPRAYWEB (Tinarelli et al, 1994, Alessandrini et al. 2013, Bisignano et al., 2017). In our approach each particle carries its own potential temperature, which evolves according to a stochastic differential equation as in Van Dop (1992). The buoyancy is calculated from the particle temperature and is directly included in the equation for the evolution of the velocity through a coupling term. We compare the concentration field simulated by the model with the results of a water tank experiment (Weil et al. 2002).