Baltic Sea

and estimated a mean deep volume transport of 0.28 km 3 /d carrying an overall mean salinity
of 13 g/kg towards the east. Starting in 2002 and ending in 2003, Piechura and
Beszczy«ska-Möller (2004) carried out altogether six detailed hydrographic surveys to
monitor the 2003 inow in the Arkona Basin, the Bornholm Basin, the Stolpe Channel, and in
the Gdansk Basin. They concluded that mainly mixed water from intermediate layers of the
Bornholm Basin makes its way into the Stolpe Channel. The largest volume of saline deep
water which entered the deeper layers of the Stolpe Channel 2 − 3 months after the inow
was rst recorded at the Darss Sill in January 2003. Borenäs et al. (2007) investigated
whether the hydraulic theory is suitable to quantify maximal transports. For comparisons with
real data long-term observations from monitoring stations in the Bornholm Basin and in the
Gdansk Basin were used. These observations revealed that the hydraulic theory is only of limited
use to estimated transports through the Stolpe Channel. Meier and Kauker (2003b)
found that a small positive west wind anomaly causes a systematically reduced eastward salt
ow above the bottom of the Stolpe Channel during stagnation periods. Furthermore, there is
some observational evidence that strong precipitation over the central Baltic catchment area
with enhanced river discharges also reduces the net deep eastward ow through the Stolpe
Channel. In contrast to Kouts and Omstedt (1993), these authors calculated the value
of 2.69 km 3 /d. It is higher by factor of about ten for the time period between 1902 and
1998. Independently from involved methodical uncertainties, this discrepancy clearly points
to the importance of longer lasting changes in prevailing winds and associated precipitation
conditions for the generation of spatiotemporal modications in internal pressure gradients
and the Baltic deep water circulation.
To obtain somewhat more insight into related processes, for the rst time, current measurements
were conducted by two ADCPs at the eastern gateway of the Stolpe Channel at 75 m
water depth, just above the northern and the southern ank of the channel. Their records
cover three months (September - December 2006). Chapter 4 describes detected uctuations
as well as related steering mechanisms.
1.7 Methodical specics
This study applies the unit g/kg for the salinity. The numerical value of absolute salinity in
grams of salt per kilogram of seawater is somewhat higher than that of the Practical Salinity
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