York river destratification: an estuary-subestuary interaction

Area of Science:

• Estuarine oceanography
• Coastal dynamics
• Hydrodynamics

Background:

• Estuaries typically exhibit two-layer flow, with distinct freshwater and saltwater layers.
• Subestuaries can experience unique flow dynamics influenced by larger estuarine systems.

Purpose of the Study:

• To investigate the causes of destratification in the York River during high spring tides.
• To understand the role of Chesapeake Bay water advection in altering estuarine flow.
• To determine if this phenomenon is unique to the York River or a common estuarine interaction.

Main Methods:

• Analysis of estuarine flow patterns.
• Observation of water advection from the Chesapeake Bay into the York River.
• Examination of salinity gradients and tidal current phases.

Main Results:

• Destratification in the York River is caused by the intrusion of less saline Chesapeake Bay water during high spring tides.
• This intrusion is driven by a longitudinal salinity gradient in the bay and phase differences in tidal currents between the river and bay.
• The observed phenomenon disrupts the typical two-layer estuarine flow.

Conclusions:

• The destratification of the York River is a direct consequence of bay water advection.
• Subestuary-estuary interactions, particularly during high spring tides, can significantly alter estuarine hydrodynamics.
• Similar destratification events may occur in other Chesapeake Bay subestuaries and are likely common in estuarine systems.