The influence of large-scale atmospheric circulation on the variability of salinity at Helgoland Roads station

The variability of April salinity at Helgoland Roads station (54.12 degrees N, 7.9 degrees E, Germany) is analysed in relationship with Elbe river discharge and the observed variability in large-scale atmospheric circulation for the period 1962-2000. It is shown that the main driver of salinity anomalies is the river discharge anomalies from the previous month. These discharge anomalies are strongly related with precipitation anomalies from the Elbe catchment area. Changes in the salinity, discharge and precipitation anomalies are accompanied by a wave train atmospheric circulation pattern that connects the tropical Atlantic Ocean with northern part of Europe, as well as with changes in large-scale water vapour transport over the whole German Bight. Positive sea-surface temperature anomalies, centred in the Caribbean region and the North Sea, are associated with positive salinity anomalies and negative anomalies of discharge and precipitation.