Articles | Volume 13, issue 3
Nonlin. Processes Geophys., 13, 353–363, 2006
https://doi.org/10.5194/npg-13-353-2006

Special issue: Turbulent transport in geosciences

Nonlin. Processes Geophys., 13, 353–363, 2006
https://doi.org/10.5194/npg-13-353-2006

  07 Aug 2006

07 Aug 2006

Penetrative convection in stratified fluids: velocity and temperature measurements

M. Moroni and A. Cenedese M. Moroni and A. Cenedese
  • Department of Hydraulics, Transportations and Roads, University of Rome "La Sapienza", Rome, Via Eudossiana 18 – 00184, Italy

Abstract. The flux through the interface between a mixing layer and a stable layer plays a fundamental role in characterizing and forecasting the quality of water in stratified lakes and in the oceans, and the quality of air in the atmosphere. The evolution of the mixing layer in a stably stratified fluid body is simulated in the laboratory when "Penetrative Convection" occurs. The laboratory model consists of a tank filled with water and subjected to heating from below. The methods employed to detect the mixing layer growth were thermocouples for temperature data and two image analysis techniques, namely Laser Induced Fluorescence (LIF) and Feature Tracking (FT). LIF allows the mixing layer evolution to be visualized. Feature Tracking is used to detect tracer particle trajectories moving within the measurement volume. Pollutant dispersion phenomena are naturally described in the Lagrangian approach as the pollutant acts as a tag of the fluid particles. The transilient matrix represents one of the possible tools available for quantifying particle dispersion during the evolution of the phenomenon.