Baltic Sea

7
6.5
a
Temperature ( o C)
6
5.5
5
M−7
M−8
4.5
Current speed (cm/s)
15
10
−5 05
0
−10
−20
30/08/97 23/09/97 18/10/97 12/11/97 07/12/97 01/01/98 26/01/98 20/02/98 17/03/98 11/04/98 06/05/98 31/05/98 25/06/98 21/07/98
Date
b
c
Figure 3.1: Daily temperature and current series of Aanderaa current meters deployed at 170 m depth
at positions shown in Fig. 1.2 and statistics compiled in Table 3.1: a) Daily temperature records ( ◦ )
of the NE (black) and SW moorings(grey). Two arrows mark the CTD surveys M-7 (before) and M-8
(during the end of the inow). Note that the warm deep water inow reached the NE mooring around
the 27 November 1997, but the SW position 30 days later. b) Stick plot of daily current speed (cm/s)
of mooring NE and c) stick plot of mooring SW; note the dierent vertical scales of b) and c). Date
displayed as dd/mm/yy.
hibit increased variability but their overall tendency remained that of the pre-inow situation.
This, however suggests that the currents of this layer roughly followed the local topography.
The northwestward currents at NE (Fig. 3.1 b) were somewhat stronger than the currents at
SW, where southward currents dominated the whole measuring period (see Fig. 3.1c). Note
the dierent vertical scales of Fig. 3.1 b and Fig. 3.1 c. With the beginning of May, the current
speed at NE became weak and its direction changed to the south for several weeks. This is
seen to be a clear indicator that the inow period terminated completely above the eastern
topographic ank of the EGB in May. Such a change in the overall current direction accompanied
by a relaxed deep water circulation was much lesser pronounced at the position SW. Here,
the overall southward direction continued for the entire recording time although the current
strength slightly weakened.
In summary, these two synchronous current series suggest a cyclonic deep water circulation
25