Robinson Hordoir, SMHI, Sweden

Influence of Sea Level Rise on the Dynamics of Salt Inflows in the Baltic Sea

Time and place
Tuesday 1 Sep 2015, 11.15
Room C609, Arrhenius Laboratory, 6th floor

The Baltic Sea is a marginal sea, located in a highly industrialized region in Central Northern Europe. Salt water inflows from the North Sea are a crucial phenomenon that affects the entire Baltic Sea ecosystem. This study explores the impact of anticipated sea level changes on the dynamics of those inflows. We use a numerical oceanic general circulation model covering both the Baltic and the North Sea. The model sucessfully retraces the essential ventilation dynamics throughout the period 1961 to 2007. A suite of idealized experiments suggests that rising sea level is associated with intensified ventilation as salt water inflows become stronger, longer and more frequent. Expressed quantitatively as a salinity increase in the deep central Baltic Sea we find that a sea level rise of 1m triggers a saltening of more than 1 PSU. This substantial increase in ventilation is the consequence of the increasing cross-section in the Danish Straits amplified by a reduction of vertical mixing.