Anhang 1: English Summary 
In 1998 the Federal Maritime and Hydrographic Agency (BSH, Bundesamt für Seeschifffahrt 
und Hydrographie) started its annual summer surveys which cover the entire North Sea 
between 52° and 60° N. The surveys were realised at a time when thermal stratification is 
expected to be at its maximum and phytoplankton production has passed its maximum (see 
Table 1). The surveys include seven coast to coast East-West sections between 54° and 60° 
N and additional stations between 54° N and the entrance of the English Channel. With the 
exception of the first survey in 1998 all surveys served a fixed station grid for vertical CTD 
and water samples. Between the fixed CTD-stations a towed CTD-system (1998-2008 the 
BSH system Delphin, since 2009 an EIVA ScanFish MK I) oscillated between a depth of 3 - 
10 m (depending on weather and sea state) and a about 5 metres above the bottom in order 
to record the 3-dimensional distribution of relevant oceanographic parameters. Both CTD- 
systems sampled T, S, fluorescence (chlorophyll-a, yellow substance), and oxygen 
concentration. Additionally, a thermosalinograph and optical sensors were mounted in the 
ship moon pool at about 4 m depth. Since 2010 the survey was extended to the north in 
order to record the transition area between the northern North Sea and the eastern North 
Atlantic. 
Additionally, water samples were collected by means of a CTD-rosette sampler-system (e.g. 
nutrient, salinity, oxygen, pH) and with 10 and 100 litre glass spheres for organic 
contaminants (5 and 50 m depth). Surface samples for the detection of artificial nuclides 
were taken at all station. 
Preliminary results: 
These first results base upon ScanFish raw data. Due to rough sea conditions the ScanFish 
could not be towed along the 54°N section and there are no data along the 59°N section east 
off 1.3°E due to winch problems. 
Temperature 
The depth of the warm surface layer is comparable to 2010, but the temperatures are about 
1 K cooler as in 2010. The surface layer covers the whole E-W section is partly vertically 
mixed along the English Coast. Total heat budget can be calculated not until detailed 
analysis after the cruise. The monthly average of the total North Sea SST in August was 0.3 
K above the 1971-1993 mean. 
Salinity 
On average the salinity distribution is also comparable to 2010. Atlantic water >35 PSU is 
detectable until 56°N. Both inflow regimes, through the Fair Isle Channel and above the east 
Shetland shelf, are distinguishable and join along the 57°N section. The Baltic outflow with a 
depth of about 20 m extends to 2°E, compared to 4°E in 2010. Also the salt heat budget can 
be calculated not until detailed analysis after the cruise. 
Seite 28 von 32