Ocean’s Carbon Sink Boosted by Uneven Bubble Dynamics, New Research Reveals
WASHINGTON D.C. – Teh world’s oceans are absorbing atmospheric carbon dioxide at a faster rate than previously understood, thanks to a newly discovered mechanism involving the asymmetric rise of bubbles, according to research published this week in Nature. The study challenges existing models of gas exchange between the ocean and atmosphere, suggesting a significantly enhanced efficiency in CO2 uptake. This finding has critical implications for climate change projections and understanding the ocean’s role in mitigating rising atmospheric carbon levels.
For decades, scientists have known the ocean acts as a massive carbon sink, absorbing roughly 30% of the CO2 emitted by human activities. Though, accurately quantifying this uptake has remained a challenge. This new research demonstrates that bubbles rising from the ocean surface aren’t simply moving in a straight line; they deform and create turbulent wakes that dramatically increase the surface area available for gas exchange. this asymmetric bubble behavior,coupled with the resulting enhanced mixing,leads to a substantially greater transfer of CO2 from the atmosphere into the ocean than previously estimated.The implications are far-reaching, potentially altering climate models and informing strategies for carbon sequestration.
the research team, led by Dr. Markus Rothacher at the University of California, Santa Barbara, utilized a combination of laboratory experiments, field measurements, and high-resolution simulations to observe and quantify this phenomenon. They found that as bubbles rise, they become flattened on one side due to the surrounding water flow, creating a larger interfacial area and inducing localized turbulence. This turbulence accelerates the dissolution of CO2 into the water.
“We observed that bubbles don’t rise symmetrically,” explained Dr. Rothacher. “This asymmetry generates a wake that significantly enhances the transfer of gas across the air-sea interface.” The team’s experiments, conducted using controlled wave tanks and field observations in the open ocean, consistently showed a 30-60% increase in CO2 transfer rates compared to models assuming symmetrical bubble rise.
Existing models of ocean carbon uptake rely heavily on parameters like wind speed and sea surface temperature. These models typically assume bubbles rise vertically and maintain a spherical shape. The new findings necessitate a re-evaluation of these parameters and the incorporation of bubble asymmetry into future climate models.
Data from the Surface ocean CO2 Atlas (SOCAT), compiled by Dlugokencky and Tans (2018), provides a crucial long-term record of atmospheric and oceanic CO2 concentrations, serving as a benchmark for validating the new findings. Furthermore, satellite-based sea surface temperature data, such as that provided by Merchant et al. (2019), will be essential for integrating the bubble asymmetry effect into large-scale climate models.
The solubility of CO2 in seawater, a basic factor governing ocean uptake, has been well-established since the work of Weiss (1974), but this research highlights how physical processes like bubble dynamics can dramatically influence the rate at which that solubility is realized.
The research team is now focused on refining their models to account for varying ocean conditions, including different salinity levels, wave heights, and bubble sizes. They are also investigating the potential impact of this enhanced CO2 uptake on marine ecosystems and ocean acidification. The findings underscore the complex interplay between physical and chemical processes governing the ocean’s carbon cycle and the urgent need for continued research to improve our understanding of this critical component of the global climate system.