Turbulent Mixing Processes in the Earth System
Juan Pedro Mellado
MPI for Meteorology, Bundesstr. 53, 20146 Hamburg
The mission of this research group is to improve our current understanding of funda-
mental aspects of geophysical turbulence using direct numerical simulation. Within the
context of the earth system, our group focuses on small-scale phenomena. These simu-
lations provide a direct measure of different properties, like time scales associated with
transients, transfer rates of mass (constituents), momentum and energy, correlations or
distribution functions, which are then analyzed in terms of an appropriate reduced set of
non-dimensional parameters. Current research focuses on: (a) evaporative cooling effects
at the cloud interface, either in a horizontal or in a vertical configuration; (b) the very
stable boundary layer, in particular the development of a code to study the turbulent
Ekman layer under different stratification profiles and stratification strengths; (c) the
convective boundary layer, in particular the detailed study of the entrainment processes
at the inversion layer and the validation of the models commonly used in the literature.
In parallel, all this work builds a data base that can be used to test low-order models
currently used and developed at the MPI for Meteorology, like large-eddy simulations and
Reynolds-Averaged Navier-Stokes equations.