24 
3.3 Harmonic Analysis: Elevations 
The results of the harmonic analysis of the water level records are listed in Table 6. Figure 9 shows 
how the semi-diurnal M 2 and S 2 amplitudes H and phases G vary from west to east along the NORA sec 
tion. Data from the “Class A Network Dataring Gauge” at the port of Wick (58° 26.5’ N, 3° 05.1’ E) are in 
cluded in Table 6 and Fig. 9 for comparison purposes (Shaw [1992a,b]). Harmonic synthesis calculations 
by means of the constituents of Table 6 indicate that the tide, as well as the tidal stream, is delayed by about 
0.5 hours between 2° W and 2° E. The synthesis shows a mean time lag of about 1.5 hours between the 
MOVENS and the NORA data. Amplitudes and phases of the Q b 0 1? K b N 2 , M 2 and S 2 tidal constituents 
can be compared with the model results given by Schwiderski [1979-1981] (see Table 7). Generally, 
the NORA amplitudes agree well with Schwiderski’s results. Most phase angles agree within a few degrees, 
but there are some positions with considerable differences, e. g. S 2 at N1. With the exception of the N 2 con 
stituent at M9, the MOVENS amplitudes are definitely larger than the model results. Some of the MOVENS 
phase angles agree well, other differ up to 126°. The possible reasons for the differing phase angles are the 
limited length of our time series (about 1 month) and the method used by Schwiderski to model ocean tides. 
The M 2 phase along the NORA section agrees better with Davis’s results [1981]. As in many pa 
pers by other authors, however, Davis investigated only the M 2 tide. Other harmonic constituents cannot 
therefore be compared. 
Table 6 
Amplitudes H and phase angles G of 17 tidal constituents calculated from tide gauge time series of 
the NORA- and MOVENS section 
Consti 
tuent 
WICK*' 
H G 
N1 
H G 
N2 
H G 
N3 
H G 
N4 
H G 
N5 
H G 
M8 
H G 
M9 
H G 
cm 
O 
cm 
O 
cm 
o 
cm 
O 
cm 
O 
cm 
O 
cm 
O 
cm 
O 
Qt 
3.2 
343 
2.5 
338 
2.2 
340 
1.4 
342 
1.5 
4 
1.7 
0 
3.5 
287 
5.1 
214 
o, 
11.7 
25 
10.0 
26 
7.9 
33 
6.0 
40 
5.5 
41 
4.6 
40 
11.1 
14 
8.9 
90 
M, 
- 
- 
1.0 
293 
1.1 
298 
0.5 
278 
1.0 
310 
1.2 
315 
3.9 
255 
15.6 
168 
K, 
10.8 
175 
10.6 
189 
8.8 
191 
7.0 
194 
5.7 
200 
4.6 
203 
7.6 
149 
13.1 
233 
J, 
0.8 
240 
0.9 
210 
1.1 
196 
0.5 
192 
0.6 
232 
0.7 
214 
1.4 
194 
2.0 
153 
MNS, 
- 
- 
0.2 
39 
1.2 
30 
0.8 
1 
0.5 
331 
0.2 
355 
4.5 
246 
8.5 
0 
M2 
- 
- 
1.0 
331 
0.6 
96 
1.1 
334 
1.4 
325 
1.1 
309 
3.9 
45 
5.5 
88 
N, 
20.3 
303 
14.1 
286 
11.3 
299 
9.7 
302 
8.1 
302 
7.0 
301 
14.5 
258 
4.2 
171 
M, 
101.7 
322 
79,4 
314 
64.2 
318 
51.3 
328 
42.4 
329 
34,9 
326 
57.9 
295 
50.9 
295 
L, 
- 
- 
3.4 
346 
2.9 
356 
1.9 
348 
1.6 
343 
1.7 
329 
6.0 
273 
8.0 
94 
S, 
35.0 
0 
28.0 
7 
23,0 
11 
19.7 
20 
16.9 
19 
14.2 
17 
31.9 
316 
32.6 
320 
MSN, 
- 
- 
1.6 
259 
1.9 
281 
0.9 
297 
0.6 
286 
1.1 
277 
5.0 
80 
7.2 
62 
2SM, 
- 
- 
2.2 
182 
1.2 
168 
1.1 
190 
0,6 
151 
0.3 
193 
2.7 
282 
7.5 
114 
M 4 
3.6 
317 
2.8 
267 
4.3 
281 
1.6 
286 
1.4 
265 
1.3 
265 
1.3 
295 
1.7 
69 
MS 4 
2.0 
51 
0.8 
2 
2.0 
348 
1.2 
21 
1.0 
8 
0.7 
25 
1.9 
280 
1.7 
85 
M 6 
0.6 
227 
1.2 
179 
1.0 
197 
0.7 
249 
0.5 
308 
0.7 
22 
0.3 
202 
0.7 
93 
2MS 6 
- 
- 
1.0 
237 
1.1 
272 
0.8 
302 
0.6 
326 
0.3 
80 
0.4 
277 
1.3 
355 
F 
0.17 
0.19 
0.19 
0.18 
0.19 
0.19 
0.21 
0.26 
f=(K l + 0,)/(M 2 + S 2 ) 
*' data from Shaw [ 1992]