Chaotic Stirring in a Tidal System

• Published in: Science (American Association for the Advancement of Science) Vol. 258; no. 5085; pp. 1107 - 1111
• Main Authors: Ridderinkhof, H., Zimmerman, J. T. F.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 13.11.1992; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Analysis; Chaos theory; Chaotic systems; Coastal oceanography, estuaries. Regional oceanography; Earth, ocean, space; Exact sciences and technology; External geophysics; Fluid shear; Lagrangian function; Marine; Ocean currents; Particle trajectories; Physics of the oceans; Random walk; Seas; Tidal currents; Tides; Topography; Trajectories; Trapped particles; Velocity distribution; Water; ANE, Wadden Sea; Wadden Sea, North Sea; Chaos; Lagrangian model; Turbulence; Stirring; Tidal current; Estuaries; Hydrodynamic dispersion; Trajectory; Flow field; Shallow water; Tidal wave; Mixture
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.258.5085.1107

An analysis of a two-dimensional tidal model of the Wadden Sea reveals Lagrangian chaos in the trajectories of water parcels. The associated chaotic stirring results from the transverse intersection of the stable and unstable curves of hyperbolic fixed points in the Lagrangian residual displacement field (the tidal Poincaré map). This tidal dispersion mechanism produces rapid water exchange along the channel axis and could be representative of many shallow tidal seas.