THE BALTIC INFLOW EVENT 2014 AND ITS BIOGEOCHEMICAL RESPONSE IN THE ANOXIC CENTRAL BALTIC BASINS

Detlef E Schulz-Bull1, Michael Naumann2, Volker Mohrholz3, Günther Nausch2 and Ralf D Prien4, (1)Leibniz Institute for Baltic Sea Research, Marine Chemistry, Rostock, Germany, (2)Leibniz Institute for Baltic Sea Research, Rostock, Germany, (3)Leibniz-Institute for Baltic Sea Research Warnemünde, Physical Oceanography and Instrumentation, Rostock-Warnemünde, Germany, (4)IOW, Rostock, Germany
Abstract:
The brackish Baltic Sea and the deeper anoxic basins in the central parts are occasionally ventilated by the intrusion of high saline and oxygen rich water from the North Atlantic entering the Baltic Sea. With a volume of 198 km3 containing 4 Gt salt, the inflow event in 2014 was the third largest ever observed. As a result the redox conditions in the anoxic parts of the Baltic Sea changed. In the Bornholm Basin and the Gotland Deep area the biogeochemical conditions for many elements and redox sensitive substances changed crucial by the inflow water. Oxidation of the hydrogen sulfide and consequent changes in the pH and the carbonate system were observed. Other chemicals such as the nitrogen nutrients, phosphate, trace metals and the dissolved organic matter react with the fresh inflow water ingredients. The chronological sequence of the biogeochemical reactions following the inflow event where monitored by autonomous stations and several ship expeditions in high spatial and temporal resolution.
Back to: Physical and Biogeochemical Processes and the Support of Shelf Sea Primary Productivity and Carbon Cycling IV Posters