| Summary: | Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732 Glacier Bay is a recently (230 years ago) deglaciated fjord located within Glacier Bay National Park in southeastern Alaska. Glacier Bay is about 100 km long along the main axis, and it has several side arms and multiple sills, which are backed by very deep basins (200-400 m) with tidewater glaciers. Glacier Bay experiences a large amount of “runoff” from melting glaciers, high sedimentation, and large tidal ranges. The freshwater inflows from melting glaciers support estuarine circulation, possibly all year-round during recent warm winters. The complex topography and strong tidal currents lead to highly variable salinity, temperature, and current patterns within a small area. To characterize the hydrodynamics of this complex system, a 3D numerical hydrodynamic model (UnTRIM) using an unstructured grid has been implemented to simulate tidal circulation and salinity distribution in Glacier Bay, Alaska. The unstructured grid used by the model allows an accurate representation of the complex basin topography. Only very limited time-series records of water levels and current measurements had been taken. Some profiling ADCP and CTD cruises provided data for qualitative comparison with results of the numerical model. An open boundary exists at the southern end of the model near Gustavus where water levels (tides) and salinity values are specified. At tidewater glaciers, freshwater releases are assumed representing melting glaciers. Preliminary model simulations show complex spatial variations of tidal current pattern and salinity distributions are also computed. The model results are qualitative and preliminary, but they shed light on the overall hydrodynamic characteristics of Glacier Bay. These results are the basis for future interactive interdisciplinary research linking hydrodynamic processes to the distribution and abundance of marine animals in Glacier Bay National Park.
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