Baltic Sea

captured eastward velocities up to 60 m on the northern ank in the water column, whereas at
the repeat transect eastward velocities reached as high as 55 m on the southern ank coincides
with the level of high eastward velocities measured by ADCP SFS on the southern ank of the
channel (see upper left panel in Fig. 4.10). The calculation of geostrophic velocities explains
only to some extent the velocities observed in the Stolpe Channel and are also just a snap
shot. To investigate the amount of water transported through the Stolpe Channel over the
three months deployment period other methods have to be applied.
4.3.3 Transports through the Stolpe Channel
The two ADCPs at the outlet of the Stolpe Channel were deployed at 75 m depth along 17.5 ◦ E
and measured currents in a 1 hour interval at either side of the channel. Their positions are
marked in Fig. 1.1. ADCP SFN was deployed at the northern ank of the channel and
ADCP SFS was deployed at the southern. Simultaneous data recordings of both ADCPs
were conducted between 23 September 2006 and 19 December 2006 (87 days), covering a
depth between 25 − 71 m. ADCP SFN (see Fig. 4.10 left panel) was a 600 kHz ADCP and
therefore covered depths between 25 − 71 m, whereas the 300 kHz ADCP SFS covered the
whole water column. Eastward ow of both ADCPs was mainly restricted to lower layers,
between 65 − 71 m for SFN and between 52 − 71 m for SFS (compare Fig. 4.13). Westward
ow predominated in the upper layers between 25 − 65 m for SFN and 25 − 52 m for SFS.
Fig. 4.10 (upper right panel) gives the impression that eastward currents reached slightly
higher up in the water column until highest eastward velocities were recorded in the beginning
of November, but afterwards moved down again until the end of the recording period. On
the northern side of the channel on three occasions (4 November 2006, 3 − 4 days after the
4 November and on 17 − 18 December 2006) a strong easterly ow was recorded throughout
the whole water column which succeeded to break up the separation between the upper and
lower layer. On the southern side of the channel (Fig. 4.10 upper right panel) the whole water
column was dominated by an eastward ow on only two occasions, the 4 November 2006 and
3 − 4 days later. It was more often observed that westerly ow dominated the whole water
column, especially after the big storm event at the beginning of November.
Model simulations of the eastward currents of SFS indicate the good agreement between
modelled and measured velocities (compare Fig. 4.11 with Fig. 4.10 upper right panel). The
59