Density and Absolute Salinity of the Baltic Sea 2006–2009

Abstract

Abstract. The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006–2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

Revisiting Remane’s concept: evidence for high plankton diversity and a protistan species maximum in the horohalinicum of the Baltic Sea

“…1. Scheme of the Baltic Sea indicating the regions and natural macroregions according to Wattenberg (1949), and mean surface-water salinity (calculated from Feistel et al 2010) (2) brackish water species, which are very eurytopic, have low rates of speciation compared to more stenotopic marine or freshwater species. The original Artenminimum conceptual assertions were largely based on the Baltic Sea hydrobiological data of Remane (1934) and best illustrated by Remane's curve (see Fig.…”

Impacts of Future Climate Change and Baltic Sea Level Rise on Groundwater Recharge, Groundwater Levels, and Surface Leakage in the Hanko Aquifer in Southern Finland

“…However, the density of the Baltic Sea is relatively low, on average 1.005 kg m ) [34]. In the Gulf of Finland, the density of seawater varies from 1.001 to 1.006 kg m ) and salinity from 3.0% to 10.23% (average 6.6%) [35]. The salinity value varies with depth, from 3.0% to 5.5% in shallow water [36] up to 10.23% at a maximum water sampling depth of 80 m [36].…”

Pre- and post-Chernobyl accident levels of 129I and 137Cs in the Southern Baltic Sea by brown seaweed Fucus vesiculosus

“…Salinity distributions in its surface layer (0e10 m) show strong horizontal gradients, with values close to 30 psu at the Kattegat area. This value decreases towards the Bothnian Bay and the gulfs of Finland and Riga, where values below 3 psu are found (Feistel et al, 2010). Vertical stratification is also noticeable (Hou et al, 2001).…”