4
Description and Error
Analysis of Field Data
One-hundred-and-one measurement tidal elevation stations with high quality
tion. These stations are scattered mostly along the coastline and continental shelf
as is shown in Figure 17. These 101 stations are used to validate the Eastcoast
2001 harmonic tidal database values by comparing simulated harmonically
decomposed tidal elevation constituents with measured harmonically analyzed
published field data. Published measured elevation harmonic constituent data is
derived from long-term records of sea surface elevation. The measured station
data are obtained from several sources: International Hydrographic Organization
Tidal Constituent Bank (IHO) 1991, U.S. Geological Survey 1984, Reid and
Whitaker 1981; the NOS Survey,1 and the NOAA. Stations are listed in Table 2.
Stations 1-34 lie along the Atlantic coastline; stas 35-60 and 82 are located in the
Gulf of Mexico; stas 61-71, 73, 75, 76, 78, 79, 81, and 88 lie in the Caribbean
Sea; and stas 72, 74 , 77, 80, 83-87, and 89-101 are scattered in the deep Atlantic
Ocean or near small islands in the Atlantic.
Most of these recording stations are located in open waters or in areas access-
ible to the adjacent open ocean. A careful study of each station's location was
conducted to ensure that the stations closely represent the open-water conditions
simulated in the computation. Table 2 provides an overview of the location of
each station by indicating if it is in the open ocean with no obstructions or the
degree of constriction to the adjacent open waters. If the stations have flow
partially impeded, the width of the opening and length of the path between open
water and the recording station are noted. Since small inlets were typically not
included in the computational domain and grid, it is important that all stations do
not lie too far away from open water and/or lie behind highly dissipative lateral
or vertical constrictions. All stations selected attempt to represent as closely as
possible the adjacent open-water tidal elevation values.
An intercomparison of the harmonic constituent values at stations with multi-
ple published measured values was performed to establish an estimate of the
reliability of the data itself. Twenty-one of the 101 stations have two sources of
published measured recorded harmonic data, one being the newest release from
NOS (2001) and the other being either IHO or a NOAA source, as listed in
1
Data obtained from National Ocean Service World Wide Web page accessed on 2 May 2001,
http://co-ops.nos.noaa.gov/data_retrieve.shtml?input_code=100201001har\.
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Chapter 4 Description and Error Analysis of Field Data