Preliminary observation of a tidal intrusion front inside the mouth of the Chesapeake Bay

In situ sampling during flooding tidal flow and southerly winds shows the up-estuary translation of a surface front along the Thimble Shoal channel, which is located in the southern part of Chesapeake Bay. Currents and surface density were measured using a towed acoustic Doppler current profiler and CTD, and a ship-borne radar was used to monitor the orientation and planform of the front, which varied over time. These preliminary observations suggest that dense shelf water, upwelled to the surface along the coast near Cape Henry, Virginia, can be found well into the southern part of the bay during flood, and that the boundary between the intruding shelf water and less dense estuarine water has many of the same characteristics as tidal intrusion fronts found in smaller scale estuaries.