Do Micro Bubbles Create Gas Exchange?

[Randy Holmes-Farley]

My un-scientific ipinion
Since the bubble is gas encapsulated in the water it wont exchange gas. It will however disturb the waters surface when it rises and pops.

The gas will equilibrate with the nearby water. It cannot do any more than that.

 

[Randy Holmes-Farley]

Excellent question!

I would think it has to help some. But then I remember reading that surface water agitation is more important than the air/water mixing that goes on in a skimmer. So I'll be interested to hear Randy's thoughts and experience.

As a general rule, that’s an opinion not usually based on actual facts or measurements. The fact that people can often raise pH by using outside air or scrubbed air in a skimmer inlet shows that there is substantial gas exchange from a skimmer.

 

[Uncle Billy]

Yes they can
David Kevin Woolf

• International Centre for Island Technology
• Energy Academy
• School of Energy, Geoscience, Infrastructure and Society
• Institute for Life and Earth Sciences

Bubbles can be generated at the sea surface by many mechanisms, but the main source is by the entrainment of air in breaking waves. Bubbles will scavenge material from the surrounding water, thus contributing to the cycling of dissolved and particulate organic material. When they burst at the sea surface these bubbles generate a sea salt aerosol contaminated with material scavenged from the sea-surface microlayer and below. Gases will be exchanged between a bubble and the surrounding water while it is submerged. In addition, the breaking waves and surfacing bubble plumes disrupt the surface microlayer, and this may enhance transfer of gases directly through the sea surface.

The net transfer of a gas between a bubble and the surrounding water, from entrainment until the bubble bursts or fully dissolves, contributes to the total transfer of that gas between atmosphere and ocean. This bubble-mediated transfer has some special properties that set it apart from direct air–sea transfer of poorly soluble gases. Bubble-mediated air–sea transfer velocities depend on the solubility in addition to the molecular diffusivity of the gas in seawater. Bubble-mediated transfer is not proportional to air–sea concentration difference, but is biased toward injection and the forcing of supersaturation. The entrainment of air by breaking waves increases rapidly in intensity with higher wind speeds.

Thanks lapin, David - Uncle Billy here: I have thought for a long time that the water oxygen levels a the seashore would be highest because of the wave action there - what appears to me an ideal, perpetual gas transfer arrangement. Moreover, it is along the coast lines that the sea water is warmest and most shallow which which would best promote photosynthesis. I have considered also that the increased pressures within breakers may further impart gas transfer 24/7/365, rain or shine - something we can truly believe and count on, regardless of who the president may be! Regards, Uncle Billy Feb. 1, 2023

 

[Randy Holmes-Farley]

Thanks lapin, David - Uncle Billy here: I have thought for a long time that the water oxygen levels a the seashore would be highest because of the wave action there - what appears to me an ideal, perpetual gas transfer arrangement. Moreover, it is along the coast lines that the sea water is warmest and most shallow which which would best promote photosynthesis. I have considered also that the increased pressures within breakers may further impart gas transfer 24/7/365, rain or shine - something we can truly believe and count on, regardless of who the president may be! Regards, Uncle Billy Feb. 1, 2023

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