The ocean’s ‘biological pump’ captures twice as much carbon as expected

Posted: April 7, 2020 by oldbrew in Carbon cycle, modelling, Ocean dynamics, research
Tags: ,

The ocean carbon cycle [credit: IAEA]


The Woods Hole researchers find ‘the efficiency of the ocean’s “biological carbon pump” has been drastically underestimated’, with inevitable implications for climate modelling and assessments. Given that the oceans hold 50 times more CO2 than the atmosphere, this must matter.
– – –
Every spring in the Northern Hemisphere, the ocean surface erupts in a massive bloom of phytoplankton, says Phys.org.

Like plants, these single-celled floating organisms use photosynthesis to turn light into energy, consuming carbon dioxide and releasing oxygen in the process.

When phytoplankton die or are eaten by zooplankton, the carbon-rich fragments sinks deeper into the ocean, where it is, in turn, eaten by other creatures or buried in sediments.

This process is key to the “biological carbon pump,” an important part of the global carbon cycle.

Scientists have long known that the ocean plays an essential role in capturing carbon from the atmosphere, but a new study from Woods Hole Oceanographic Institution (WHOI) shows that the efficiency of the ocean’s “biological carbon pump” has been drastically underestimated, with implications for future climate assessments.

In a paper published April 6 in Proceedings of the National Academy of Sciences, WHOI geochemist Ken Buesseler and colleagues demonstrated that the depth of the sunlit area where photosynthesis occurs varies significantly throughout the ocean.

This matters because the phytoplankton’s ability to take up carbon depends on amount of sunlight that’s able to penetrate the ocean’s upper layer.

By taking account of the depth of the euphotic, or sunlit zone, the authors found that about twice as much carbon sinks into the ocean per year than previously estimated.

The paper relies on previous studies of the carbon pump, including the authors’ own. “If you look at the same data in a new way, you get a very different view of the ocean’s role in processing carbon, hence its role in regulating climate,” says Buesseler.

“Using the new metrics, we will be able to refine the models to not just tell us how the ocean looks today, but how it will look in the future,” he adds. “Is the amount of carbon sinking in the ocean going up or down? That number affects the climate of the world we live in.”

In the paper, Buesseler and his co-authors call on their fellow oceanographers to consider their data in context of the actual boundary of the euphotic zone.

Full article here.

Comments
  1. Ian W says:

    “Scientists have long known that the ocean plays an essential role in capturing carbon from the atmosphere, but a new study from Woods Hole Oceanographic Institution (WHOI) shows that the efficiency of the ocean’s “biological carbon pump” has been drastically underestimated, with implications for future climate assessments.”

    When the ocean pump reduces the level of CO2 in the atmosphere to below 150ppm, and plants start dying followed by all animal life, will scientists still consider that removal of ‘carbon’ from the atmosphere is ‘essential’?

  2. oldbrew says:

    Remember the ‘pump’ is a two-way process, depending on prevailing conditions.


    – – –
    Study: Enhanced CO2 outgassing in the Southern Ocean from a positive phase of the Southern Annular Mode (2007)
    Positive phases of the SAM are associated with anomalous outgassing of natural CO2

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006gb002900

  3. cognog2 says:

    There is a similarity here with the Hydro Cycle energy pump which drives energy in the form of Latent Heat upwards in the atmosphere for dissipation with some of it escaping to space via the cirrus clouds. Most this due to the buoyancy of water vapor wrt dry air. Sadly a process which doesn’t get a look in where the models are concerned.

  4. gbaikie says:

    “Using the new metrics, we will be able to refine the models to not just tell us how the ocean looks today, but how it will look in the future,” he adds. “Is the amount of carbon sinking in the ocean going up or down? That number affects the climate of the world we live in.”

    With more carbon sinking more plant life, and more fish, giving more food to humans and whales and etc.

  5. oldbrew says:

    If ocean heat content rises that should lead to more CO2 outgassing, and the opposite if oceans cool.

  6. Chaswarnertoo says:

    More CO2 available, more life, more sequestered ‘carbon’. Homoeostasis by Gaia.

  7. gbaikie says:

    “More CO2 available, more life, more sequestered ‘carbon’. Homoeostasis by Gaia.”

    We are living in Ice Age and living near starvation in terms of CO2 {in atmosphere}.

    And Earth has had warmer times. So it seems Earth has had a lot more life.
    The question is how much more life.
    And we had more life on land- simply because Ice Ages have more deserts [and more grasslands].
    Or more forests globally when not in an Ice Age.
    But what about the worlds oceans, was there more life in ocean in non Ice Age times?

  8. oldbrew says:

    Carbon Cycling in the World’s Deepest Blue Hole
    Scientists find new extremes as they research carbon cycling in the Yongle blue hole.

    SOURCE: Journal of Geophysical Research: Biogeosciences

    The researchers found the lowest concentrations of dissolved organic carbon ever recorded in coastal waters. At the same time, they found some of the highest concentrations of dissolved inorganic carbon in similar conditions. Both the organic and inorganic carbon molecules were much older than carbon found at parallel depths in the open ocean.

    https://eos.org/research-spotlights/carbon-cycling-in-the-worlds-deepest-blue-hole

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