Table 2: Monthly North Sea area-averaged SSTs and anomalies SST in 2018 (Reference 
period 1971-1993) 
| Apr ı May | June | Jul | Aug | Sep 
4.8 | 63 , 13.5 | 16.2 17.0 | 15.0 
2018 | Jan | Feb | Mar 
°C | 70 
K 1041 0.4 | 
Temperature 
The water temperatures along the zonal (east-west) 54° N section are completely vertically 
mixed due to low water depths, the 55° N section is vertically mixed along its shallower 
gastern part. From 55° N (deeper western part only) and up to 60° N all sections show a 
massive, homogeneously mixed surface layer with a strong thermocline at about 30 m depth 
which grows weaker along the UK coast due to strong tidal currents. The temperatures of the 
upper mixed layer resemble those of the 2017 survey, which was carried out about one 
month early in August when SSTs were at their seasonal peak. 
Salinity 
At the surface the salinity sections show a relative narrow inflow of Atlantic Water (S >35 
osu) over the East Shetland Shelf and the Fair Isle Channel which is also visible on the 59° N 
section but not on southern sections. In the bottom layer there is a broad inflow over the 
entire section reaching southward with a small tip to 56° N. This southern tip is part of an 
isolated column of Atlantic Water which extends from bottom to surface. At the southern 
connection between North Sea and Atlantic, the eastern approach to the Strait of Dover, no 
Atlantic Water was detected. The total salt budget will not be calculated prior to the final 
orocessing of the data and the analysis of the in-situ salinity samples for CTD calibration. 
Where the ocean meets the sky. Peter Löwe 
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