Scaling the Bubble Penetration Depth in the Open Ocean during the Southern Ocean Gas Exchange Experiment 2008

An effective wave-scale parameterization was used to explore the observed penetration depths of bubble plumes under open ocean conditions. This particular parameterization was based on a momentum and energy balance across the atmospheric wave boundary layer during the Southern Ocean Gas Exchange Experiment in 2008. The wave-scale was considered to be the largest actively wind-coupled wave in a swell dominated wave field. Bubble plume penetration depths were measured from acoustic backscatter anomalies and their presence in the water column was independently corroborated through optical measurements at comparable depths. These results suggest that bubble plumes that were initially injected by wave breaking were transported down into the water column at depths proportional to the wind-coupled wavelength i.e. the effective wavelength. Significant wave heights do not scale the observed penetration depths. Nonetheless, significant wave heights appear to scale the expected energy deviations from a rigid-wall due to the presence of waves. This suggest their relevance related to the energetics of the injection and not to the actual penetration depth or the length scale of the transport.