Oxygen measurements in aquatic environments are often used to quantify net community production (NCP), a key parameter in the marine carbon cycle. Physical conditions such as wind speed and bubble distributions cause variations in air-sea gas exchange, directly impacting dissolved gas concentrations. Variations in these conditions affect the accuracy of oxygen flux estimations and, in turn, produce a major source of uncertainty in NCP calculations. To improve gas exchange estimates, especially at high wind speeds, dissolved oxygen concentrations were continuously measured using an optode while varying physical conditions in the SUrge STructure Atmosphere InteractioN (SUSTAIN) wind-wave tank at the University of Miami Rosenstiel School of Marine and Atmospheric Science. Conditions varied included wind speed, wave type, and water temperature. Physical parameters such as short-scale surface roughness, wave amplitude and water velocity were continuously monitored. Noble gas concentration ratios were measured using mass spectrometry and bubbles in the water were imaged using shadowgraph techniques. Analysis of saturation anomalies and flux are presented as a way of examining the impact of different physical parameters on air sea-gas exchange. This study is part of a broader effort to use gases, primarily noble gases, in order to better understand the effects of bubbles and high winds on gas transfer in a controlled environment. In this presentation, we will primarily discuss the oxygen data but we will also refer to insights gleaned from other gases.

Examining the effect of air-sea gas exchange on dissolved oxygen concentrations at varied physical conditions in a wind-wave tank

256th National Meeting (2018)

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