Table 2: Monthly North Sea area-averaged SSTs and SST anomalies in 2019 
(Reference period 1971-1993) 
2019 | Jan | Feb | Mar | Apr | May | June Sep 
°C | 76] 67] 70 | 791] 9.6 | 12.6 | 15.0 117.6 | 14.8 
K | 10 1018312105106 [0671 16T] 
Temperature 
Due to an unusual high intensity of solar radiation during the first days of the cruise, there 
was a moderate temperature stratification along the zonal (east-west) 54° N section. This 
section is normally completely vertically mixed due to tidal mixing and low water depths. The 
same was observed along the shallow eastern part of the 55° N section. The deeper western 
part of the 55° N section and all sections up to 60° N showed 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. In the Norwegian Trench the thermocline had 
deepens to about 100 m. The temperature difference between surface and bottom 
temperature was greater 10 K at the deep stations in the Skagerrak and about 8 K in the 
central North Sea. 
Salinity 
As in the previous year, there was a relative narrow inflow of Atlantic Water (S >35 psu) over 
the East Shetland Shelf and the Fair Isle Channel in the surface layer which was also visible 
on the 59° N section but not on southern sections. In the bottom layer a broad inflow over the 
entire northern sections down to 58°N was observed reaching southward with a small tip to 
56° N. At the southern connection between North Sea and Atlantic, the eastern approach to 
the Strait of Dover, a small tongue of Atlantic Water was detected in both layers extending 
north-eastward up to Station GN010 west off Den Helder. The total salt budget will not be 
calculated prior to the final processing of the data and the analysis of the in-situ salinity 
samples for CTD calibration. 
Fig. 6: Choppy waters (© H. Klein) 
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