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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No substitute for actual observations in the supposedly settled science of carbon cycling. What Olympian hubris consensus “climate science” suffers.
That is not a “depth error” that is a stuff up. The notion that CO2 partial pressures might cary with depth is hardly PhD stuff. Sounds pretty much like “climate science” business as usual though. Nothing really to see here folks, move along.
Friends:
The article says
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. I have repeatedly said it on WUWT most recently in the Salby thread which discussed the carbon cycle for weeks
http://wattsupwiththat.com/2013/08/11/murry-salby-responds-to-critics/#comment-1391907
where I wrote
{emphasis added: RSC}
Indeed, this has been a major disagreement between Ferdinand Engelbeen and me in our debates of the carbon cycle which has been vigorously contested for over a decade.
It is good to see climate science at last catching up with what has always been obvious.
Richard
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 ?
Now in quiet (unroiled) surface waters, we usually find a negative Temperature gradient with depth, except for the top few microns of surface water, where evaporative cooling occurs.
But then there is a significant drop in Temperature with depth, leading to increasing CO2 and other solubility increase with depth.
This would establish a downward diffusion of CO2 from the surface driven by the solubility gradient.
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
If solar heating warms the surface layer, the outgassing of CO2 will be diminished by the fact that the surface CO2 is depleted below its Henry’s law value by the Temperature gradient pumping.
So please, can I see some real MEASURED CO2 versus depth, with enough resolution to see what is really going on.
I’m a skeptic as to their thesis; they need to convince me with measurements, not models.
With the now overwhelming failure of atmospheric climate models clearly visible we now see the battle of conjecture and assertion of climate alarmism moving more and more to the even less researched field of the oceans. This research does not bode well for the credibility of all the alarmists that have now started to use hyperbole in the extreme in trying to assert that man made CO2 emissions are going to destroy all ocean life by 2100 based on the ph bogeyman they have conjured up. The fact that the natural variability of ocean chemistry has huge ranges which even the limited field research shows doesn’t seem to phase the ocean alarmists. They claim that a change of 0.3 to 0.4 in ph will be devastating to marine life. The fact that already existing filed measurements of ocean ph show this parameter varies by many factor larger than this amount doesn’t enter their arguments.
It’s a pity the Calleja paper is pay-walled.
…next thing you know, they will discover algae and plankton
Chemistry is easy…..chemical biology is hard
I see some complaints about this paper for using existing data sets to infer a theory. However, i respect any authors who but out a theory and recommend that experimental data be gathered to prove/disprove it.
george e. smith:
At August 31, 2013 at 3:45 pm
http://wattsupwiththat.com/2013/08/31/co2-calculation-in-the-glovbal-carbon-cycle-may-be-off-due-to-a-depth-error/#comment-1404970
You ask
No, I don’t think you did “detect” that because the article says
and this agrees with the abstract of the paper which says
So, it seems your rant about not using measurements is mistaken because the entire analysis is based on measurements.
Richard
Latitude says:
August 31, 2013 at 3:57 pm
…next thing you know, they will discover algae and plankton
Chemistry is easy…..chemical biology is hard
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Biology, the only science where multiplication and division are the same thing….
Ursus Augustus says: August 31, 2013 at 3:34 pm
‘That is not a “depth error” that is a stuff up. The notion that CO2 partial pressures might cary with depth is hardly PhD stuff. Sounds pretty much like “climate science” business as usual though.’
Notice something here? The disgram used to illustrate, with bio cycles and all, is from the NOAA site. No-one doubts that details of CO2 exchange at the surface are complex. Still, it happens, and when people observe CO2 at 10m depth or whatever, it shows that it got there.
[diagram? Mod]
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 huge surface area of water droplets in precipitation systems.
It would also explain the CO2 rich surface layer.
Nick, it just shows that it’s there…not that it got there
biological processes in the ocean work just like they do on land…there’s a reason it is aerobic
Google Scholar search for reports and papers on gas mass transfer at gas-liquid interface
http://scholar.google.com/scholar?as_q=&as_epq=&as_oq=%22mass+exchange%22+turbulence+surface&as_eq=&as_occt=any&as_sauthors=%22sanjoy+banerjee%22&as_publication=&as_ylo=&as_yhi=&hl=en&as_sdt=0%2C33
Use Sanjoy Banerjee as author and keywords for mass transfer at interfaces, including turbulence, to find many.
Yet another example about how little supposed experts know. The AGW advocates make financial and military analysts look like geniuses in comparison.
If this is true, which wouldn’t surprise me as mainstream activists tend to have nil interest in finding and correcting subtle CAGW-movement- convenient errors, if the oceans have been less of a CO2 sink than commonly assumed, that means more of human CO2 emissions have to be going somewhere else (for observations place a limit on increase in the atmosphere), which means more into vegetation and soil. So CO2 fertilization bonuses are likely even greater than previous mass exchange calculations would suggest. The real picture would include talking properly about beneficial extra vegetation growth, rather than trying to hide its mention with just so-called “missing sink” references.
The problem with all this CO2 ocean-cycling info is the pitiful state of the data and thus our understanding of the magnitude and importance of natural processes.. Take a few hundred (at best) measurements under certain constrained ocean conditions and you do have some data.
The problem, though, is that there is poor understanding of NON_SAMPLED conditions and places. Did they take samples in nasty weather with massive seas and spume entraining the atmosphere – increasing molecular transport by orders of magnitude perhaps ? ETC. etc. Did they take random replicated samples in large enough series to get rigorous statistical significance ? 99.9 percent chance of NO.
Until we do the observational science that yields accurate evaluations of the importance and magnitude of the myriad physical & biological processes controlling the gas exchange between ocean and atmosphere. we are essentially blind.
Robert JM
Right on. It continues to amaze me that the role of fresh water (which has lots of CO2) and ice (which has none) in the carbon cycle gets so little attention. It is obvious that 1 meter of rainfall with 1125 pm CO2 going into the ocean which are 620ppm makes a difference. Whatever gas exchange is taking place they should add 3 billion tons of CO2 per metre of rainfall.
These are not small influences, taken together.
Oh, now it starts to dawn on some of them that Earth may not be a black body after all.
” that cannot be explained by Henry’s Law alone,”
That alone renders a great deal of past comment redundant.
This observational data tends to support the sun warmed oceans as the primary source for natural CO2 and the increased vegetation on land as a complete (or nearly so) sink for human emissions:
http://www.newclimatemodel.com/evidence-that-oceans-not-man-control-co2-emissions/
Am still waiting for the paper that concludes “This topic has been studied enough. No more money should be spent. We are going to do something else.”
So they recon that only 11% of the excess CO2 at the surface compared to 5 meters depth is explicable by Henry’s Law. The implication is that 89% of the excess or 11.5 micro atm is biological. Ferdinand claims that the atmospheric pCO2 is 7 micro atm above equilibrium with the ocean. One wonders with the surface or at 5m? If Ferdinand’s ships were sampling at 5m, his 7 atmospheric surplus becomes a 6 atmospheric deficit in relation to the surface, essentially changing sign.
What would this mean? Carbon Dioxide loves to swim. This proclivity plus a small net biological sink or even a biological balace would mean the atmosphere cannot supply the ocean fast enough to achieve equilibrium.
And this doesn’t even address errors in estimates of volcanic CO2 emissions. Chances are, there’s a warmist thumb on every measure of CO2 in the global carbon cycle.
But does this make us any less doomed?