R. Steven Nerem (University of Colorado, United States); J. Toby Minear (University of Colorado, United States)

Tidal propagation directly influences salinity gradients, sediment transport and habitat dynamics in estuarine ecosystems. This study investigates the spatial and temporal dynamics of tidal propagation and the influence of ocean tides and sea level change within the Delaware and Chesapeake Bay estuarine systems. The Surface Water and Ocean Topography (SWOT) satellite mission provides a new technique for monitoring water surface elevations in estuarine systems. The primary SWOT data products used in this analysis are the 100x100m and 250x250m raster products and the pixel cloud (PixC) product. Following cross-validation with in-situ measurements from NOAA tide gauges and USGS stream gauges, we quantify signal attenuation and phase changes of ocean tide propagation and the spatial reach within riverine-estuarine systems. We evaluate how bay geometry and local bathymetry modulate tidal harmonics and flow dynamics by relating these metrics to observed spatial variations. Furthermore, the tidal range profile is evaluated for each estuarine reach. Preliminary results reveal amplification of tidal signals in upstream reaches of both systems, and identify reach-scale zones that may become tidally flood-prone under projected sea level change.