Lagrangian analysis of long-term dynamics of turbulent superstructures

In Rayleigh‐Bénard convection, turbulent superstructures are large‐scale patterns of circulation rolls created by hot ascending and cold descending thermal plumes. The evolution of these large‐scale patterns happens on very large time scales τ. Spectral clustering applied to Lagrangian particle trajectories on time intervals smaller than τ can be used to create clusters displaying a structure similar to the patterns detected in the Eulerian frame of reference. However, this technique is unfeasible for the analysis of the evolution of turbulent superstructures due to turbulent dispersion. Therefore, we test the application of concepts of evolutionary spectral clustering on Lagrangian particle trajectories to analyze the long‐term dynamics of turbulent superstructures in the Lagrangian frame of reference.