Overall the Eastcoast 2001 tidal database has significant improvements in
Eastcoast databases. Within each subregion, the dominant tide(s) achieved the
greatest improvement. Along the Atlantic coastline, error in the dominant tidal
constituent, M2, reduced from 9.3 percent in the Eastcoast 1995 to 5.6 percent in
Eastcoast 2001. As expected in the Gulf of Mexico, errors in the dominant
astronomical constituents, K1 and O1, reduced by over half. This tremendous
decrease in amplitude errors within the Gulf is partly due to the updated
bathymetry of the Great Bahama Bank. In the Caribbean Sea, most of the errors
stayed about the same except for the S2 constituent for which errors were reduced
by half. At the remote stations, there were no significant improvements from
Eastcoast 1995 to Eastcoast 2001, indicating that the extra resolution added to
the deep Atlantic Ocean was most likely not necessary for accuracy reasons in
these tidal simulations. The phase error improvements were more modest than
the amplitude error gain. Nonetheless the semidiurnal constituents phases
improved significantly in the Atlantic.
Estimated errors for measured field data, from Chapter 3, were also included
in the bar charts, Figures 147-151. The errors in the measured field data itself
will affect the error analysis between the computed and measured data. In the
figures, the measured data error estimates are roughly half the computed to
measured data's error values. This indicates that a significant proportion of the
errors estimated for Eastcoast 2001 can be attributed to the uncertainty of the
measured field data, and not to the inaccuracy of the numerical computations.
Eastcoast 2001 tidal database simulations were computed on 128 IBM
Power3 SMP machines at the U.S. Army Engineer Research and Development
Center, Major Shared Resource Center (ERDC, MSRC) in Vicksburg, MS. A
90-day simulation took 58 wall clock hours on 128 processors.
20
Chapter 5 Model Results