PHASE DEFECTS AS A MEASURE OF DISORDER IN TRAVELING-WAVE CONVECTION

Spatiotemporal disorder is studied in traveling-wave convection in an ethanol-water mixture. A technique for calculating the complex order p arameter of the pattern is described, and the identification of phase defects is demonstrated. Point defects, domain boundaries, and standin g wave patterns are shown to produce unique defect structures. The tra nsition from a disordered state to a more ordered pattern is described in terms of the dynamics of defects and their statistics.