Chesapeake Bay Analysis using Time and Spatial Generalized Eigenfunctions

A Normal Mode Analysis of the Chesapeake Bay has reached the phase of performing time-series analysis. Prior attempts using generalized eigenfunctions obtained from COMSOL have led to extraction of power spectra using a partial domain extraction and a wavelet-like correction to the result. A new approach has been developed which effectively solves the spatial equivalent of the Initial Value Problem. By taking data sets at a limited number of points (about 10) over extended periods of time the Chesapeake Bays flow vector field can be extracted from the power spectra. This method combines the spatial modes derived from COMSOL with the generalized basis set for time. By overlaying windows of the spectra obtained, a progression of the spectral components is obtained for the lowest 100 eigenmodes. This progression can exhibit smooth behavior which allows for prediction of the modal behavior to take place, effectively predicting the flow across the entire Bay while only sampling the Bay at 10 locations. Presented at the 2007 COMSOL Users Conference Boston, 4-6 Oct, Newton. MA. Supported in part by ONR.