6
deployed along 61° 51’ N between 1° 30’ E and 4° 10’ E. For all NORA and MOYENS instruments, the
sampling interval was 10 minutes, except for the deepest MOYENS instruments which were acoustic Neil-Brown
current meters with a sampling interval of 1 minute.
The N1 to N5 NORA moorings and the M8 and M9 MOYENS moorings were additionally equipped
with Aanderaa water level recorders. Deployment positions, sampling depths, and soundings are given in
Table 1. All instruments returned full records.
Table 1
Deployment statistics
Position water sampling depths
Id
laditude
longitude
depth
current meters
WLR
m
m
m
m
m
m
m
’’NORA“ July/August 1990
N1
59°
0.16’ N
1°
59.85’ W
80
24,
46,
66,
78
-
77
N2
59°
0.10’ N
1°
0.30’ W
129
22,
63,
100,
127
-
126
N3
59°
0.19’ N
0°
0.57’ W
138
25,
66,
109,
-
-
135
N4
59°
0.02’ N
1°
0.31’ E
125
22,
63,
96,
123
-
122
N5
59°
0.23’ N
2°
0.43’ E
116
13,
21,
62,
114
-
113
N6
58°
59.95’ N
3°
29.94’ E
210
21,
73,
124,
156,
208
-
N7
59°
0.10’ N
4°
10.11’ E
295
16,
67,
256,
293
-
-
N8
58°
59.90’ N
4°
44.88’ E
280
16,
68,
149,
251,
278
-
’’MOYENS*
* September/October 1986
M6
60°
28.90’ N
3°
31.60’ E
312
117,
189,
247,
304
-
-
M7
61°
50.37’ N
2°
2.87’ E
375
70,
120,
225,
288,
365
-
M8
61°
50.57’ N
1°
29.79’ E
355
90,
163,
226,
286,
348,
236
M9
61°
50.95’ N
3°
0.19’ E
413
60,
130,
240,
300,
403,
280
MIO
61°
51.71’ N
4°
9.55’ E
210
55,
75,
126,
176,
205
-
Id = mooring identifier, WLR = water level recorder
2 Residual currents and volume transports
This section describes volume transports and residual currents at the NORA and MOYENS sections.
To eliminate inertial and tidal motions, periods shorter than 24.48 hours are removed using a Gaussian lowpass
filter. Volume transports were calculated from the low-passed meridional velocity components, averaged
over the length of the respective time series (see Tables 2 and 3). The box contours (Fig.3) are placed
right between the current meters (horizontal lines) and mooring positions (vertical lines), respectively.
2.1 The NORA section (July/August 1990)
The water exchange across the NORA section is dominated by the northward outflow of the Norwegian
Coastal Current (NCC) and the southward inflow of Atlantic Water (AW) at the western edge of the
Norwegian Trench. In the upper layer, the NCC is the continuation of the Baltic Current, a narrow wedge of
low salinity water close to the coast, and a wider section of mixed North Sea water. The day to day variability
of the NCC and AW transports is greater than their mean values (Otto et al.[ 1990]). The boundary between
the NCC and the inflow of AW is characterized by great mesoscale variability which manifests itself
in mesoscale meanders and eddies (Ikeda et al.[l989], Johannessen et al.[1989]). Between 58.5°N
and 59° N the continuous AW inflow is blocked by a submarine ridge (cf. Fumes et al. [1986]). Through
a combination of topographic steering and Ekman transport, most of the AW inflow makes a cyclonic turn
and flows back northwards with the NCC (Tu rre 11 [1992a]).
