A TECHNIQUE TO MEASURE THE REAL SURFACE TENSION ON A BUBBLE

Abstract: The surface tension of water is a key parameter for assessing the degree of contamination of harbours, ports and open waters. However standard methods of measuring surface tension do so at the flat air/water interface at the top of a body of water, whereas in for many important processes, this is not the manifestation of surface tension that is most important. For biogenic decomposition, air/sea gas exchange, the production of aerosols (all three of which are known to be important for climate on a global scale), as well as the behaviour of ship wakes and their effects (in distributing contaminants in the water column, affecting the local sound field or the ship’s acoustic signature), and in the harvesting and transportation of petrochemicals, it is the surface tension on the wall of bubbles within the water column that matters. This paper explores a technique that can measure the surface tension on a bubble wall, and compares it with the surface tension measured at the air/water interface. Any difference would mean that modelling of the above effects, based on measurements of surface tension on the flat air/water interface, would contain systematic errors with global implications