FYSISK MILJÖ I BOTTNISKA VIKEN / The Physical Environment of the Gulf of Bothnia
The Gulf of Bothnia makes about 29 % of the whole water volume of the Baltic Sea. The water exchange between the Baltic Proper and the Gulf is good, which results in a water renewal time of only about 4 to 5 years. This is one of the reasons why there is no lack of oxygen in the deep water of the Gulf of Bothnia, which often is the case wnh the deep warer of the Baltic Proper. The dynamics and thermodynamics of the Gulf of Bothnia are guided by hydrological, meteorological and, partly, topographical factors, such as freshwater supply, wind over sea, sun radiation, sea ice and sill depth between the subbasins.