Arctic carbon conveyor belt discovered; ‘the surprise was great’

Posted: November 22, 2022 by oldbrew in atmosphere, Carbon cycle, Ocean dynamics, research, sea ice
Tags: ,

The ocean carbon cycle [credit: IAEA]

Nature’s carbon cycle works even better than was believed. The researchers say ‘it can be assumed that the global influence of this mechanism as a carbon sink is actually much greater’.
– – –
Every year, the cross-shelf transport of carbon-rich particles from the Barents and Kara Seas could bind up to 3.6 million metric tons of CO2 in the Arctic deep sea for millennia, says Science Daily.

In this region alone, a previously unknown transport route uses the biological carbon pump and ocean currents to absorb atmospheric CO2 on the scale of Iceland’s total annual emissions, as researchers from the Alfred Wegener Institute and partner institutes report in the current issue of the journal Nature Geoscience.

Compared to other oceans, the biological productivity of the central Arctic Ocean is limited, since sunlight is often in short supply — either due to the Polar Night or to sea-ice cover — and the available nutrient sources are scarce.

Consequently, microalgae (phytoplankton) in the upper water layers have access to less energy than their counterparts in other waters.

As such, the surprise was great when, on the expedition ARCTIC2018 in August and September 2018 on board the Russian research vessel Akademik Tryoshnikov, large quantities of particulate — i.e., stored in plant remains — carbon were discovered in the Nansen Basin of the central Arctic.

Subsequent analyses revealed a body of water with large amounts of particulate carbon to depths of up to two kilometres, composed of bottom water from the Barents Sea. The latter is produced when sea ice forms in winter, then cold and heavy water sinks, and subsequently flows from the shallow coastal shelf down the continental slope and into the deep Artic Basin.

“Based on our measurements, we calculated that through this water-mass transport, more than 2,000 metric tons of carbon flow into the Arctic deep sea per day, the equivalent of 8,500 metric tons of atmospheric CO2. Extrapolated to the total annual amount revealed even 13.6 million metric tons of CO2, which is on the same scale as Iceland’s total annual emissions,” explains Dr Andreas Rogge, first author of the Nature Geoscience study and an oceanographer at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI).

This plume of carbon-rich water spans from the Barents- and Kara Sea shelf to roughly 1,000 kilometres into the Arctic Basin. In light of this newly discovered mechanism, the Barents Sea — already known to be the most productive marginal sea in the Arctic — would appear to effectively remove roughly 30 percent more carbon from the atmosphere than previously believed.

Moreover, model-based simulations determined that the outflow manifests in seasonal pulses, since in the Arctic’s coastal seas, the absorption of CO2 by phytoplankton only takes place in summer.

Understanding transport and transformation processes within the carbon cycle is essential to creating global carbon dioxide budgets and therefore also projections for global warming.

On the ocean’s surface, single-celled algae absorb CO2 from the atmosphere and sink towards the deep sea when aged out. Once carbon bound in this manner reaches the deep water, it stays there until overturning currents bring the water back to the ocean’s surface, which takes several thousand years in the Arctic.

And if the carbon is deposited in deep-sea sediments, it can even be trapped there for millions of years, as only volcanic activity can release it.

This process, also known as the biological carbon pump, can remove carbon from the atmosphere for long periods of time and represents a vital sink in our planet’s carbon cycle.

Full article here.

  1. Graeme No.3 says:

    What this means for Global Warming believers.

  2. […] Arctic carbon conveyor belt discovered; ‘the surprise was great’ […]

  3. It is a little sick that they study a Carbon Sink when Water is abundant, ice is abundant, water vapor is abundant, and they do not study water in all of its changing states as the primary regulator of climate cycles. Warm times have less ice extent, open Arctic Ocean, more evaporation and snowfall and sequestering of ice. Ice always advances at the end of warmer times with more ice accumulation. Ice advance causes colder, they never study this.

  4. Sorry, my mistake, it is much more than just a little sick.

  5. Phoenix44 says:

    “…a vital sink…”

    Only if you believe sequestering carbon for millenia is somehow a good thing. Why would anybody think that?

  6. oldbrew says:

    In light of this newly discovered mechanism, the Barents Sea — already known to be the most productive marginal sea in the Arctic — would appear to effectively remove roughly 30 percent more carbon from the atmosphere than previously believed.

    Nature doing its work.

  7. Jaime Jessop says:

    “We could show that the co-location of dense water formation and transport with elevated biological production in the Barents Sea impacts the carbon budget of the Arctic Ocean by retaining substantial amounts of carbon in the deep Nansen Basin while providing a food source for deep sea organisms. The Barents Sea, however, is not the only shelf region with such co-location. For example, the Sea of Okhotsk, the Bering Sea or around northern Greenland19,42 and, in particular, the Antarctic Ross43 and Weddell seas44,45,46 are characterized by dense water formation and primary production, and it is therefore probable that high carbon injection rates also occur there as well. Moreover, high-density bottom waters produced around Antarctica47 can lead to even deeper injection with longer retention times than reported here for the Arctic Ocean.”

    It’s taken them FOUR years to analyse the data from the Barents Sea and the data says that the deep sea sequestration of carbon is much greater than previously assumed and that the underestimation may apply to other regions of the Arctic AND the Antarctic, which would substantially affect their carbon budget calculations I imagine. Did they mention this at COP27? I must have missed that part. The ‘speed of science’ apparently is much slower than the speed of politically motivated climate change alarmism.

  8. daveburton says:

    It annoys me that the authors of papers like these rarely use units that would be meaningful to most readers. “Up to 3.6 million metric tons of CO2 [per year]” = 0.0036 Gt CO2 = 0.0010 PgC = 0.00045 ppmv CO2.

    You can compare that to anthropogenic CO2 emissions which total about 5 ppmv per year, or to total natural CO2 sinks of about 2½ ppmv per year. So the authors of this paper, if it is correct, have identified the cause of about 1/5500-th of the natural carbon sinks which remove CO2 from the air. 🥱

    Strangely, neither the article nor the paper uses the word “negligible.”

  9. michael hart says:

    It’s painful sometimes, watching someone crawling towards asking the questions that others do immediately.

    The circumpolar oceans are often cited as far more productive than others. Productive fisheries at the top of the eco-pyramid are built on photosynthetic CO2 uptake. During summer the poles receive as much sunlight as the equator.
    If the FLUX of sea ice increases then so will this carbon sink.
    Physically, the downwelling of saline water probably will too.
    So many answers, not enough questions from the climatists.

  10. oldbrew says:

    Does this 2013 article tell the same story?

    Oceans May Absorb More Carbon Dioxide

    Plankton may absorb more of the CO2 causing climate change than previously thought, according to new research
    March 20, 2013

    “How much carbon is attached to each molecule of nitrogen or phosphorus just used to be [considered] a constant,” said Francois Primeau, a co-author on the paper and an associate professor of Earth system science at UC Irvine.

    But that’s not the case. For example, in warm zones near the equator that are low on nutrients, the ratio of carbon to nitrogen to phosphorus measured was 195:28:1; in cold, high-latitude regions with plenty of nutrients, the ratio changed to 78:13:1. Redfield’s ratio is 106:16:1 oceanwide.
    . . .
    Because the ratios vary by latitude, the plankton may actually take more or less carbon with them as they sink down to the ocean floor, depending on where they are.
    [bold added]
    – – –
    Since warm water absorbs less CO2 by volume than cool water, this isn’t hard to figure out? As the link above puts it: ‘variations correlated with latitudes’.

    …the well-known fact that cold water holds more dissolved gases than warm water.

  11. […] Arctic carbon conveyor belt discovered; ‚the surprise was great‘ — Tallbloke’s Talkshop […]

  12. […] Arctic carbon conveyor belt discovered; ‘the surprise was great’ […]

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