close
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 May 29;8(1):8301.
doi: 10.1038/s41598-018-25818-6.

Asymmetric transfer of CO2 across a broken sea surface

Timothy G Leighton  1 , David G H Coles  2 , Meric Srokosz  3 , Paul R White  2 , David K Woolf  4
Affiliations

Asymmetric transfer of CO2 across a broken sea surface

Timothy G Leighton et al. Sci Rep. .

Abstract

Most estimates of the climatically-important transfer of atmospheric gases into, and out of, the ocean assume that the ocean surface is unbroken by breaking waves. However the trapping of bubbles of atmospheric gases in the ocean by breaking waves introduces an asymmetry in this flux. This asymmetry occurs as a bias towards injecting gas into the ocean where it dissolves, and against the evasion/exsolution of previously-dissolved gas coming out of solution from the oceans and eventually reaching the atmosphere. Here we use at-sea measurements and modelling of the bubble clouds beneath the ocean surface to show that the numbers of large bubbles found metres below the sea surface in high winds are sufficient to drive a large and asymmetric flux of carbon dioxide. Our results imply a much larger asymmetry for carbon dioxide than previously proposed. This asymmetry contradicts an assumption inherent in most existing estimates of ocean-atmosphere gas transfer. The geochemical and climate implications include an enhanced invasion of carbon dioxide into the stormy temperate and polar seas.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Photograph showing subsurface bubble clouds (taken by T.G.L.).
Figure 2
Figure 2
Photographs of the spar buoy being deployed and at sea. (a) The 11 metre long buoy being deployed from the ship (perspective makes the lower grey section appear shorter than the upper yellow section, although in reality it is nearly twice as long). (b) The buoy sitting in calm waters during the first cruise and (c) the buoy during the deployment described in this study. See also Fig. S2.3.
Figure 3
Figure 3
Bubble size distributions (BSDs) from this and historical studies. The BSDs measured in this study are shown by the broken and solid lines, measured at depths of 1.15 and 2 metres respectively. The graph compares these data with historical measurements. The historical data include the open ocean data of Breitz and Medwin (crosses), Phelps and Leighton (plus signs), Farmer and Vagle (stars) and Johnson and Cooke (dots), and the surf zone data of Deane and Stokes (diamonds), Phelps et al. (triangles), Meers et al. (downward pointing triangles) and Leighton et al. (squares).
Figure 4
Figure 4
Bubble size distributions from the measured data (dashed line with crosses) and the model (circles). Panel (a) shows the distributions at 1.15 m depth and (b) shows them at 2 m depth. The uncertainty bars show one standard deviation from the mean within these data.
Figure 5
Figure 5
The modelled flux of bubble-mediated gas transfer plotted against saturation for the four gases considered. An injection of gas is predicted at saturation, while balanced at a supersaturation, δ. The fluxes have been normalised such that the values are proportional to the rate of change of saturation of each dissolved gas. Generally, both δ and the rate of change reduce with increasing solubility.
Figure 6
Figure 6
Measured and modelled bubble size distributions for mean significant wave heights of 3.1 m (circles) and 1.9 m (triangles). Measurements are shown by open circles (Hs = 3.1 m) and open triangles (Hs = 1.9 m). The model fits are shown by filled circles (Hs = 3.1 m) and filled triangles (Hs = 1.9 m).
Figure 7
Figure 7
The bubble clouds at the end of the model run. The helical flow of the Langmuir cells can be seen. The population shown here is from a run with 100000 bubbles in each input population, and only 1 in every 100 bubbles is plotted (the larger bubbles being shown red, the smaller ones blue). Details of the input parameters can be found in Supplementary Section 3.
See this image and copyright information in PMC

References

    1. Ciais, P. et al. Carbon and other biogeochemical cycles. In: Climate Change: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [(eds) Stocker, T. F et al.] (Cambridge University Press) (2013).
    1. Rhein, M. et al. Observations: Ocean. In: Climate Change: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [(eds) Stocker, T. F et al.] (Cambridge University Press) (2013).
    1. Takahashi T, et al. Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans. Deep-Sea Res. II. 2009;56:554–577. doi: 10.1016/j.dsr2.2008.12.009. - DOI
    1. Watson AJ, et al. Tracking the Variable North Atlantic Sink for Atmospheric CO2. Science. 2009;326:1391–1393. doi: 10.1126/science.1177394. - DOI - PubMed
    1. Shutler JD, et al. FluxEngine: A flexible processing system for calculating atmosphere-ocean carbon dioxide gas fluxes and climatologies. J. Atmos. Oceanic Technol. 2016;33(4):741–756. doi: 10.1175/JTECH-D-14-00204.1. - DOI

LinkOut - more resources