Marine System Analysis Group

Results from the long-term deployment in the Byfjord during summer 2010. The upper panel shows a slight increase in oxygen concentrations, while the middle and lower panels show stable conditions for salinity and temperature, respectively. Click the figure for a larger version.

Between 19 June and 26 July a package of instruments was deployed at 20 metros depth in the Byfjord. Every night the instruments measured changes in temperature, salinity and oxygen concentrations. The results are shown in the Figure to the left.

Over the measurement period it was found that salinity and temperature remained constant. Temperature changed between 7.7 – 7.8°C while salinity hovered around 31.8. Such stable conditions are to be expected at 20 metros depth since it is below sill depth and the water exchange is limited to turbulent diffusive processes.

The oxygen concentration, on the other hand, seems to have risen slightly over the month. However, it remains below 1 micro molar throughout the measurement period and indicates severe hypoxia. The oxygen increase is not due to our pumping efforts since it commenced in mid-July, in the latter part of the long-term deployment.