Dynamical characteristics from a lagrangian study

If a number of drogues are continuously tracked during a sufficient period of time, not only average flow characteristics (shear, vorticity, divergence and stretching) but parameters of small-scale oscillatory motions (scales of eddies, their life times and translations, as well as eddy coefficients) can be computed. To do this, a computational technique is developed using the Obukhov-Kolmogorov hypothesis of cascaded energy transfer in horizontally isotropic fields. Lagrangian field experiments in Eastern Long Island Sound and Southern Lake Champlain were used to test the method. It is demonstrated that turbulent parameters are closely related to average kinematic properties of the flow.