It seems that a simple assumption about where to measure CO2 in the ocean surface has drastic implications. via The Hockey Schtick
New paper finds global carbon cycle datasets may be biased
A paper published today in Global Biogeochemical Cycles finds prior calculations of the global carbon cycle may be erroneous because such calculations are based upon partial pressures of CO2 from several meters below the ocean surface instead of CO2 levels at the ocean surface [“the boundary layer”] where CO2 is actually exchanged between the atmosphere and ocean.
The authors find a “strong” CO2 variability between the global datasets measured from several meters below the surface in comparison to the ocean surface that cannot be explained by Henry’s Law alone, and are primarily due to variations in biological activity between these layers. The paper finds higher levels of CO2 in the boundary layer than in the 5 meter deep global datasets, which would suggest that either the oceans are less of a sink for CO2 or a larger source of CO2 to the atmosphere than previously assumed.
The authors recommend, “Observations of pCO2 just beneath the air-sea boundary layer should be further investigated in order to estimate possible biases in calculating global air-sea CO2 fluxes.”
The paper:
Prevalence of strong vertical CO2 and O2 variability in the top meters of the ocean
Maria Ll. Calleja et al
Abstract:
The gradient in the partial pressure of carbon dioxide (pCO2) across the air-sea boundary layer is the main driving force for the air-sea CO2 flux. Global data-bases for surface seawater pCO2 are actually based on pCO2 measurements from several meters below the sea surface, assuming a homogeneous distribution between the diffusive boundary layer and the upper top meters of the ocean.
Compiling vertical profiles of pCO2, Temperature and dissolved oxygen in the upper 5-8 meters of the ocean from different biogeographical areas, we detected a mean difference between the boundary layer and 5 [meters below the surface] pCO2 of 13 ± 1 µatm. Temperature gradients accounted for only 11 % of this pCO2 gradient in the top meters of the ocean, thus, pointing to a heterogeneous biological activity underneath the air-sea boundary layer as the main factor controlling the top meters pCO2 variability.
Observations of pCO2 just beneath the air-sea boundary layer should be further investigated in order to estimate possible biases in calculating global air-sea CO2 fluxes.
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Interesting paper. It has always puzzled me how more carbon dioxide entering the atmosphere each year from all sources, in theory, should be causing a warmer atmosphere, yet according to the IPCC’s AR4, it is only the 3% of this CO2 from human activity that is of concern, and is so dangerous to the planet, and must be regulated. How the overwhelming 97% of CO2 entering the atmosphere each year from natural sources is of no consequence, according to the IPCC, beats me! But then, I’m not a global warming alarmist and, to me, the IPCC’s hypothesis is illogical!
Merv – can you site a specific Ch, or page(s) or diagram for your remarks re AR 4 ? I would like to read this myself. Thanks !
Mervyn says: August 31, 2013 at 11:24 pm
….. it is only the 3% of this CO2 from human activity that is of concern…
Amazing concept when you think of it:
That the biosphere was perfectly and intricately balanced for millenia in terms of CO2 production and absorption, apparently never varying from those output levels as it would not have been able to take up a few percent increase in output, as is evidenced by the doctrine that the 3% that mankind is recently adding to the mix has tipped the whole thing out of kilter.
There’s a reason why all life forms use carbonic anhydrase to accelerate the hydration/dehydration of CO2/carbonic acid: it is a lot slower than a diffusion-controlled reaction.
upon partial pressures of CO2 from several meters below the ocean surface
Is this actually true. You mean to tell me that they have been measuring CO² exchange well below the interface? That is stupid, really stupid.
What is meant by the red arrow labelled ”Fuel CO2”. I presume red for danger but as far as the ocean/algal growth/animals are concerned it is just CO2. No difference, No danger.
Oh, and radiocarbon dating where sample has at some point resided near warm oceans need careful error analysis.
Case in point, the eruption of Thera.
Maybe off topic ,but…Is night air different…?
Somewhere long ago i read that during the day carbonic acid gas is beaten down to the ground or surface by the sun.I was just wondering if that is true,might that not be another variable that is not taken into account?I also think that other gases and elements are changed(oxidation and other processes)by the sun and other elements.That is why they do experiments in the lab,isn’t it?I’m curious because i don’t hear much about those variables.
I’m commenting about this because the title/article is about errors in the calculations and if you ask me there seems to be alot.
Thanks for the interesting articles and comments.
mbur:
re your post at September 1, 2013 at 5:57 am, you say
Almost nothing is known and understood about the carbon cycle.
And the Bern Model of the carbon cycle (used by the IPCC) is certainly wrong.
If you want an introduction to various views on the carbon cycle then I commend that you read the long thread below the recent WUWT ‘Salby’ article at
http://wattsupwiththat.com/2013/08/11/murry-salby-responds-to-critics/
I hope this is helpful.
Richard
I luv’ed dat purty picture/graphic labeled Ocean Carbon Uptake. It was obviously created by a highly partisan proponent of CAGW who wanted to portray, front n’ center, the “human-caused” factor.
Who else would have put that big “red” arrow on it with the label of “(fossil) fuel CO2 uptake” …. when in fact, if anything, it should have been “clouds” with precipitation falling
Anyway, after reading the seeded commentary and all the posts, it is of my opinion that the comment posted by …. Robert JM – August 31, 2013 at 4:25 pm …. says it all … or all that was needed to be said. To wit:
“The AIRS data clearly shows high precipitation areas have lower atmospheric CO2 than Low precipitation areas. Rain absorbs CO2 from the atmosphere and moves it into the oceans. Gas exchange is minor at the ocean surface in comparison the to (sic) huge surface area of water droplets in precipitation systems. It would also explain the CO2 rich surface layer.”
The only known factual quantity associated with the above discussion is the CO2 ppm as recorded at Mona Loa, Hawaii. Everything else is estimations, speculations or obfuscations.
The other obvious fact is that the ocean water is in control of the bi-yearly cycling and the current overall average increase in atmospheric CO2 ppm. Which gives cause as to why atmospheric CO2 ppm increases/decreases always lags behind near surface temperature increases/decreases.
@richardscourtney,thanks for the info/link about the …various views.
RoHa says:
August 31, 2013 at 11:04 pm
“But does this make us any less doomed?”
Every time the rug is pulled out from under the feet of the IPCC, it becomes more difficult for them to claim they can predict the future.
So this is just part of the ongoing collapse of government propaganda in general; in this case affecting the government’s science propaganda.
This paper in the introduction says:
34 [2] Early interest in the subject of air-water gas transfer
35 arose from the need to understand the aeration of anoxic
36 waters, and has continued due to the need to track dissolved
37 pollutants, greenhouse gases, and other geochemical com-
38 pounds. A large amount of literature exists on the subject,
39 including recent reviews [Banerjee and MacIntyre , 2004].
40 In spite of this body of work, the mechanisms that drive the
41 process remain poorly understood and consequently pre-
42 dictions have large uncertainty. For example, widely used
43 predictive models of the gas transfer process commonly
44 differ by factors of three or more, and contain poorly
45 understood non-linearities [Banerjee and MacIntyre ,
46 2004]. This translates to uncertainties of at least 300% in
47 recent attempts to calculate a net oceanic CO2 uptake
48 [Donelan et al. , 2002; Takahashi et al. , 2002]. Such
49 uncertainty is due to the highly variable nature of correlat-
50 ing factors, e.g., wind, waves, surfactants, and thermal
51 convection or stratification.
which indicates that commonly used correlations ( aka parameterizations ) can differ by factors of three or more. [ my em ]
NB that the modeling approach used in the paper focuses on the fluid motions at the gas-liquid interface, not the difference in the concentration between the gas and liquid. A very much improved approach, in my opinion, as shown by the several successful applications of the approach. These applications will be among the hits that Google Scholar will find.
Given that the objectives of many GCM calculations are to determine the effects of changes in the atmospheric concentration of CO2, and that the natural flows of CO2 are enormous compared with the effects of human activities, I suspect that the GCM calculations are done with specified values of atmospheric concentrations. That is, small errors in modeling of the natural flows, and these are solely very rough estimates, could annihilate the requirement that the concentration be in agreement with the actual, or hypothesized, values.
There is a reason why a properly properly designed aquarium has filters that turn the water over a minimum of three times an hour with five being much better. Its called the boundary layer. Any serious aquarist knows this. I am strongly suspecting that the reported estimates of CO2 from organic sources are deliberately accounting for only a fraction of what actually exists. Never underestimate the power of fungi!
The hard-to-measure complications discussed here are one of the reasons that computing the AGW contribution to temperature change is “a wicked problem,” as Judith Curry called it.
Earth’s atmosphere is entirely biological (except Argon). Nitrogen from the biological Nitrogen cycle, Oxygen and CO2 from respiration/photosynthesis. Atmospheric CO2 is not a pool, it is part of a flowing system. Biological carbon fluxes are 30 times larger than “anthropogenic”.
The CO2 rapidly is “consumed” by photosynthesis, as shown by the obvious annual oscillation in the measured ppm levels. Calling the pre-industrial natural fluxes 100 percent, then fossil fuel addtions have increased since 1800. In 1800 the CO2 in ppm terms was 300, all natural. The carbon cycle input (and output) then increase to 101 percent around 1900, then reach 102 percent around 1950, and finally 103 percent in 2000.
Eventually, “anthropogenic” CO2 will cause the input to reach 104 percent, with the output adapting to the higher levels fairly quickly, within 5 to 10 years. Since the atmospheric CO2 due to anthropogenic addition is only 3 percent, then the current composition of 400 ppm can only be 3 percent anthropogenic, ie .03 times 400 is 12 ppm. And 386 ppm is natural.
The remaining 86 ppm above 300 from 1800 is natural by default. There are other sources (isotopes, etc) that show that the change from 300 to 400 ppm is 5/6 natural and 1/6 anthropogenic.
Peter Dietze said this in 1996
http://www.john-daly.com/carbon.htm
Peilke Sr has a good paper on the problems with boundry layers
http://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf
george e. smith says:
August 31, 2013 at 3:45 pm
“CO2 preferentially diffuses to deeper colder water, rather than shallower warmer water, so a continuous CO2 pumping process occurs, depleting the surface waters in CO2… ”
George – this beautiful picture is my education for the week! The obvious has a way of hiding in plain sight. Solubility gradient as an inexorable pump. This conjures up a picture of CO2 plunging to the depths pulling more CO2 out of the atmosphere to follow it, and then being released when this water wells back up to the surface somewhere else to be heated (and pumped back into the atmosphere. There is now no doubt in my mind that biological activity, as large a phenomenon as it is at and near the surface, is much overwhelmed by the dissolution and evolution of CO2 with spatial variations in sea water temperatures. I, too, would like to see a real data profile of CO2 from the sea surface both ways, up and down. When the warm surface evaporates and rises up to form cooler clouds, the cool water droplets suck in CO2, pumping it out of the atmosphere according to Henry’s Law until if falls back as cool rain to the surface – here, the CO2, already dissolved in the water, easily joins the ocean solution – another “feedback” not accounted for.
Question, once the CO2 is dissolved in water, does it lose its so-called “heat trapping” ability – most of it ceases to be molecular CO2.
On August 31, 2013 at 3:34 pm, richardscourtney writes:
“For many years and in many places I have been saying that biological activity in the ocean surface layer means Henry’s Law is not applicable for calculation of air/ocean CO2 exchange.”
At the risk of being overly pedantic, Henry’s Law (properly exercised) is definitely applicable in influencing the interchange of CO2 across gas-liquid interfaces such as (1) the seawater – air interface, (2) the rain droplet – air interface, or (3) seawater – wave entrained air bubble interfaces. . . at least as long a the concentration of biological matter has a low surface areal fraction (i.e., it’s not a dominant feature of the true surface). For each of the interfaces mentioned above, Henry’s Law sets the equilibrium gas concentration at the liquid side of the interface, and boundary layer mass transport relationships (often correlated to dimensionless parameters such as the Sherwood and Schmidt numbers) govern kinetics across the interface. So in my opinion Henry’s Law is definitely not irrelevant.
Having written this, factors such as the advection of CO2 via rain, injection from wave froth, or near surface biological activity may have a contributing (even dominating) influence on CO2 uptake or release. . .
But as a mere metallurgist/materials engineer, I’m not sufficiently educated to determine which mechanism(s) actually control the outcome. . . but in my field the final outcome often involves a competition among mechanisms. As much as CAGW modelers may not like it, in my experience Mother Nature doesn’t make things simple!
Dan
There is a lot of biological activity in the atmosphere as well. The closer to the surface the more biology.
DanMet’al:
For purpose of clarity, I write to sat that I agree all you say in your post at September 1, 2013 at 1:46 pm.
However, and importantly, none of that alters my view that biological activity in the ocean surface layer means Henry’s Law is not applicable for calculation of air/ocean CO2 exchange. Indeed, it goes some way to explaining it.
Richard
Would someone with actual access to this paper confirm or refute that “Compiling vertical profiles of pCO2, Temperature and dissolved oxygen in the upper 5-8 meters of the ocean from different biogeographical areas” means actual measurements were used?
Tku.
richardscourtney:
I acknowledge that your perspective about the role of biological activity may be correct. But given that Henry’s Law dictates the local (infinitely thin) boundary condition between atmosphere and ocean/water (rain/froth); please educate me as to how one could even formulate a model for CO2 trasnfer without considering the constraint the law imposes upon the results of calculation. [Note: if you distrust Henry’s Law because the associated solution thermodynamics is incomplete (because of interaction effects, experimental errors etc.) as typically used or discussed in this thread, I whole-heartedly agree].
But I ask only that you tell me how/why you dismiss Henry’s Law as relevant . . . is it because you don’t trust chemical thermodynamics or something else? I’m just trying to learn/understand.
Thanks in advance.
Dan
Kip Hansen says:
September 1, 2013 at 2:05 pm
I went to the paper link. . . the paper has been approved but is currently being edited and has not be typeset. I attempted to get the paper digitally from a university library where I have privileges (the paper was not available). . . If you figure out how to get it, please post.
Dan
DanMet’al:
re your question to me at September 1, 2013 at 2:20 pm.
Obviously, I have not been clear. Sorry. I will try to do better here.
I do not say I “dismiss Henry’s Law as relevant”.
I say, and have here said repeatedly, Henry’s Law is not applicable for calculation of air/ocean CO2 exchange.
This is because the effects of biota add and subtract CO2 from the air and ocean they contact. They also alter pH in ways which are not overcome by the carbonate buffer. None of these effects are quantifiable at present. And the ocean surface layer is rich in microorganisms.
Please note that Henry’s Law pertains to the equilibrium state and the presence of biota will change the equilibrium. However, if there were sufficient information to construct a mechanistic model of the air/ocean CO2 exchange then that model would need to include Henry’s Law. Unfortunately, the effects of biota are not known so cannot be modeled.
For example, effects of varying pH will be enormous. An unmeasurably small change of average ocean pH by 0.1 would induce a rise in atmospheric CO2 concentration greater than the 280 to 400 ppmv said to have happened since the industrial revolution.
Despite this, some people do use Henry’s Law to calculate air/ocean CO2 exchange and this naive calculation is providing indications which must be erroneous but nobody can know how much they are in error.
Richard
“””””……The authors find a “strong” CO2 variability between the global datasets measured from several meters below the surface in comparison to the ocean surface that cannot be explained by Henry’s Law alone, and are primarily due to variations in biological activity between these layers. The paper finds higher levels of CO2 in the boundary layer than in the 5 meter deep global datasets, which would suggest that either the oceans are less of a sink for CO2 or a larger source of CO2 to the atmosphere than previously assumed……””””””
“”””””……Did I detect that the authors do not state that they actually MEASURED the CO2 in these water layers, but inferred them from some data about biological entities ?……””””””
“”””””……So, it seems your rant about not using measurements is mistaken because the entire analysis is based on measurements. ……..””””””
Now I must have read their words incorrectly; I thought they had based their analysis on “Global Data Sets”.
If I wanted to analyse the ocean CO2 uptake, I would find a nice undisturbed oceanic location without significant tidal or current disturbances, or ships passing through, and I would carefully measure CO2 concentrations simultaneously at a variety of water depths from the very top surface micron, or less, to whatever depth was of interest. They evidently thought five metres was a useful depth.
I would do that sort of measurement regimen at a number of different such quiet locations.
I would have no interest whatsoever in ANY global data sets collected by other parties, I would MAKE MY OWN MEASUREMENTS.
No, I didn’t read where they said they did make their own measurements; that accounts for why I asked the question.
And Richard, if that is your idea of a rant, perhaps you need to take some yoga classes.