Oxygen concentration – the sensor measures the amount of dissolved oxygen in the water.
The oxygen enters the water at the surface where the atmosphere is in contact with the water.
The uptake increases width turbulent activity, such as waves.
Oxygen level is greatest at the surface and this can give oceanographers information about for how long water has been at the surface.
Oxygen content in the water can also indicate how long a water mass has been left untouched, ie not renewed by mixing with other bodies of water.
This is because organisms (like bacteria) use the oxygen so that the oxygen concentration over time will decrease. In this way, the oxygen content can be a measure of the age of the water.
Because of this, oxygen is used as kind of "trace element" and characteristic of a particular water mass.
Measured in mg / l, but data shown is percent oxygen saturation.
