A description of tides near the Chesapeake Bay entrance using in situ data with an adjoint model

Time series of surface elevation and current velocity in the vicinity of the Chesapeake Bay entrance are assimilated into a linear, barotropic model using an iterative adjoint method. Tide surface elevations, NOAA‐NOS tidal data, moored acoustic Doppler current profiler (ADCP), and ocean surface current radar (OSCR) data are included in the assimilation. Data are analyzed for three tidal constituents (M2, S2, O1); tidal series are constructed from these constituents and then used in the model assimilations. Statistics of predicted currents compare favorably with those calculated from data not used in the assimilation. An error analysis of the data distribution is performed for the M2 tidal component, showing lower errors near assimilation data series but large errors, particularly for velocity, at some locations. Addition of a hypothetical current mooring dramatically reduces errors over most of the domain. We believe these results give the most demonstrably accurate description now available of tidal currents for this region of strong currents and heavy shipping.