The Impact of Tidal Straining and Advection on the Stratification in a Partially Mixed Estuary

Stratification and mixing of the water column is an important dynamic process in estuary, which plays a significant role estuarine circulation, mass transport energy exchange. Based on multi-station synchronous observation data from 26 February to 6 March 2011 during dry season North Channel Changjiang Estuary, Richardson number, Simpson number potential anomaly were calculated analyze tidal variation stratification processes. The roles depth-mean straining, longitudinal advection, non-mean straining stirring processes analyzed by calculating contribution terms time-derivative anomaly. results show that have spatiotemporal variation. Stability gradually decreases neap tide spring tide. In reaches salt wedge migration, permanent develops mean tide, with stability increasing flood decreasing ebb, dominated advection. During periodic develops, development its breakdown advection stirring. main saltwater intrusion, ebb flood, straining. occurs, controlled assisted Channel, stratifying agent migration reaches, intrusion.