sets of dashed lines corresponding either to 5 and 10 percent amplitude error or
10- and 20-deg phase difference.
Ideally when the tidal symbols are plotted, they will fall on the one-to-one
ratio line, indicating that the simulated values exactly match the field values. If
predicted and if they fall above the line the Eastcoast 2001 computations over-
predicted. The majority of the results fall at least within the 10 percent amplitude
and 20-deg phase error range or better, and most of the dominant tidal constituent
in each region can be found within the 5 percent amplitude and 10-deg phase
error range. Note that phase errors for some of the smaller tidal constituents such
as the Q1 and K2 can be very large at some stations such as sta 66 at the Curacao
Antilles, and sta 68 at Cumana, Venezuela. However, the corresponding ampli-
tudes are extremely small, which could account for its large phasing errors since
smaller waves are more susceptible to phase misalignment in the harmonic
decomposition of the measurement data.
For each harmonic constituent, plots of amplitude and phase errors are pro-
vided at each station throughout the domain in Figures 132-145. The symbols at
each station location signify which error range it belongs in; the red color indi-
cates overprediction, whereas the blue color indicates underprediction.
The accuracy of the simulated tides was further quantified by comparing the
amplitude and phases of the seven astronomical constituents simulated at the
101 elevation recording stations to the measured field data. The measured data
used the most up to date values when multiple values were available at the
station. The computed to measured amplitude error for each constituent j was
calculated for the entire domain, Atlantic coast, Gulf of Mexico, Caribbean Sea,
and the remote stations in the Atlantic Ocean, as a proportional standard
deviation as:
1/ 2
L computed
2
∑
( xl , yl ) - η j
^ meas ( xl , yl )
η j
^
l =1
E c--amp
m
=
(9)
2
L
j
∑ ηmeas ( xl , yl )
^ j
l =1
where
L = the total number of elevation stations within a given
region
( xl , yl )
= the location of an elevation station
ηcjomputed ( xl , yl ) = the computed model elevation amplitude for constituent j
^
ηmeas ( xl , yl ) = the measured elevation amplitude for constituent j at
^j
18
Chapter 5 Model Results