Effect of CO2 levels on phytoplankton.
Story submitted by Don Healy
This article opens up a whole new vista into the relationship between CO2 levels, oceanic plant growth and the complex relationships that we have yet to learn about in the field of climate science. If phytoplankton respond like most plant species do, we may find that the modest increases in CO2 levels we have experienced over the last 50 years may actually create a bounty of micro plant growth in the oceans, which would in turn create the food supply necessary to support an increase in the oceans’ animal population.
At the same time, it would explain where the excess atmospheric CO2 has been going; much of it converted into additional biological matter, with only a limited existence as raw CO2.
There may well be a naturally balancing mechanism that explains how the earth was able to survive atmospheric levels of CO2 as high as 7000 mmp in past geologic history without turning into another Venus. Just surmising of course, but this fits with what we know about the response of terrestrial plants to elevated CO2 levels, so it is a plausible theory. Hopefully more studies along this line can clarify the situation.
From the article:
The diatom blooming process is described in the article by Amala Mahadevan, the author of the study and oceanographer at WHOI, as inextricably linked to the flow of whirlpools circulating the plants through the water and keeping them afloat.
“[The study’s] results show that the bloom starts through eddies, even before the sun begins to warm the ocean,” said Ms. Mahadevan.
This study explains the causation of phytoplankton’s phenology—the reasons behind the annual timing of the microscopic plant’s natural cycle—as it is influenced by the ocean’s conditions.
“Springtime blooms of microscopic plants in the ocean absorb enormous quantities of carbon dioxide, much like our forests, emitting oxygen via photosynthesis. Their growth contributes to the oceanic uptake of carbon dioxide, amounting globally to about one-third of the carbon dioxide we put into the air each year through the burning of fossil fuels. An important question is how this ‘biological pump’ for carbon might change in the future as our climate evolves,” said researchers.
WHOI describes the study as being conducted by a specially designed robot that can float just below the surface like a phytoplankton (only much, much larger). Other robots, referred to by WHOI as “gliders” dove to depths of 1,000 meters to collect data and beam it back to shore. Together, the robots discovered a great deal about the biology and nature of the bloom. Then, using three-dimensional computer modeling to analyze the data, Ms. Mahadevan created a model that corresponded with observation of the natural phenomena.
Full story:
http://www.thebunsenburner.com/news/cause-of-north-atlantic-plankton-bloom-is-finally-revealed/
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Eddy-Driven Stratification Initiates North Atlantic Spring Phytoplankton Blooms
Abstract
Springtime phytoplankton blooms photosynthetically fix carbon and export it from the surface ocean at globally important rates. These blooms are triggered by increased light exposure of the phytoplankton due to both seasonal light increase and the development of a near-surface vertical density gradient (stratification) that inhibits vertical mixing of the phytoplankton. Classically and in current climate models, that stratification is ascribed to a springtime warming of the sea surface. Here, using observations from the subpolar North Atlantic and a three-dimensional biophysical model, we show that the initial stratification and resulting bloom are instead caused by eddy-driven slumping of the basin-scale north-south density gradient, resulting in a patchy bloom beginning 20 to 30 days earlier than would occur by warming.
Bart says:
July 24, 2012 at 8:28 am
Nonsense. You are applying Henry’s Law inappropriately and, most egregiously, violating conservation of mass.
Bart, you obviously don’t know where you are talking about. Henry’s Law is that for a given temperature and salinity the ratio between CO2 in the atmosphere and in solution is fixed at equilibrium. If there is no equilibrium, the fluxes are in ratio with the (partial) pressure difference. That holds as good for the warm side as for the cold side. Thus any increase in the atmosphere will reduce the inflows at the upwelling side and increase the outflows at the downwelling side. After a few decades, the inflows and outflows are again in equilibrium, even with a continuous stream of increased CO2 at the upwelling side. That is very elementary physics, but that involves a term that doesn’t exist in your formula, as nothing points to the effect of the CO2 levels in the atmosphere on the flux rates as well as on the source side as on the sink side.
And talking about conservation of mass, where does the human emissions go?
Nonsense. A) This is based on your estimate from unreliable and unverifiable ice core data history B) it isn’t atmosphere to sea surface temperature which matters for this particular mechanism, but atmosphere to upwelling ocean water.
A) This is based on the influence of temperature on the CO2 solubility of seawater, see:
http://my.net-link.net/~malexan/Appendix%20B.htm Fig.2
B) The deep ocean temperature is rather fixed around 5°C and didn’t change in the past decades (no “hidden” heat content increase found in the deep oceans), neither did the concentration change in such a short time. What changed is the surface temperature: a change of 0.4°C over 50 years. That gives an increase of a few ppmv: 20 ppmv for 5°C increase or 4 ppmv/°C at 380-400 ppmv, according to the solubility curve to get back into equilibrium, but as the deep ocean upwelling is richer in CO2, the real pCO2 of the ocean surface can reach 750 microatm with the higher local temperature, thus a extra higher temperature will have a higher effect, but decreasing over time. Still far from the 70 ppmv you expect…
It is arbitrary and capricious, and it makes no sense when the slope perfectly matches the slope of the CO2 rate of change.
Again: a completely spurious correlation for the trend part, not based on any known physical process…
The influence of temperature is limited in time and effect: maximum a few decades for a temperature change of 1°C and maximum 16 ppmv, completely surpassed by the human emissions in less than 4 years.
Occam’s Razor specifies the simplest explanation which agrees with all the observations is generally the correct one.
Your explanation violates a lot of observations: the mass balance, the d13C levels, Henry’s Law, Le Châtelier’s principle and the observation that the oceans are a net sink for CO2. Proven wrong on at least these 5 points. Mine matches the trend and all other observations, only needs a better explanation of the temperature dependent variability of the sinkrate…
Ferdinand Engelbeen says:
July 24, 2012 at 1:24 pm
“Bart, you obviously don’t know where you are talking about.”
Wow, if that isn’t severe projection!
“After a few decades, the inflows and outflows are again in equilibrium…”
You have ZERO basis for that timeline. All the data indicate otherwise, including those provided by your links.
“That gives an increase of a few ppmv: 20 ppmv for 5°C increase or 4 ppmv/°C at 380-400 ppmv, according to the solubility curve to get back into equilibrium…”
You just don’t get it. There is a continuous pipeline of CO2 rich water upwelling. You can equilibrate with some elemental volume coming up in a discrete packet, but in this case, the packets keep on coming. And, they do not stop until such a time as you have as much CO2 continuously downwelling as you do upwelling. To insist, as you do, that equilibrium ensues regardless of the balance of inflow and outflow is a gross violation of mass balance principles.
“Again: a completely spurious correlation for the trend part, not based on any known physical process…”
Again, you cannot just pick and choose which parts to keep, and which to throw away, based on your predetermined conclusion. This is circular reasoning – that part is “spurious” because it would indicate insignificant human contribution to the overall CO2 level, and there is significant human contribution because those parts you don’t like are “spurious”.
You have stood the scientific method on its head. You adapt your hypothesis to fit the data, NOT the data to fit the hypothesis!!!
Furthermore, I have given you a physical process to explain it which you stubbornly refuse to understand or countenance: continuous deep ocean upwelling.
“Your explanation violates a lot of observations: the mass balance, the d13C levels, Henry’s Law, Le Châtelier’s principle and the observation that the oceans are a net sink for CO2.”
YOUR explanation does all that. In particular, your jejune invocation of Le Châtelier’s principle could as easily be turned around to say that the system will resist human inputs, the only difference being that is precisely what the data tell us it is doing!
Bart says:
July 24, 2012 at 1:54 pm
And, they do not stop until such a time as you have as much CO2 continuously downwelling as you do upwelling.
Bart, can’t you read? That is exactly what I have shown: With only 16 ppmv increase (or less, according to the solubility graphs) in the atmosphere, there is a decrease in CO2 inflow and an increase in CO2 outflow, sufficient to bring these two back into equilibrium, for a 1°C temperature increase, regardless of the initial deep ocean upwelling.
There is no influence from an increase of CO2 in the atmosphere in your formula, thus no feedback resisting the injection of extra CO2 (that is Le Châtelier’s principle) and therefore you can have any unlimited increase in CO2 from a small increase in temperature which doesn’t exist in the real world.
because it would indicate insignificant human contribution to the overall CO2 level
There is anyway a significant contribution of humanity, directly injected into the atmosphere, at twice the observed increase. Any significant contribution from a natural process múst me compensated by a siginificant sink process that removes halve the human emissions + the natural contribution in total mass, or you are violating the overall mass balance. In that case, the oceans need to remove more CO2 than the natural contribution delivers to the atmosphere. Which is what is observed. Thus an extra input from the deep oceans is mainly more circulation through the atmosphere and has a limited influence on the observed increase.
YOUR explanation does all that. In particular, your jejune invocation of Le Châtelier’s principle could as easily be turned around to say that the system will resist human inputs, the only difference being that is precisely what the data tell us it is doing!
The carbon cycle system will resist all extra inputs, no matter if that is from the deep oceans or from human emissions, in the same way, as the system doesn’t differentiate between the origin of the extra CO2. In all cases, the increase in the atmosphere reduces the oceanic releases (but can’t do that for human emissions or bacterial decay of vegetation) and increases the oceanic and land vegetation uptake. But that mechanism is exactly what lacks in your formula.
For the rest, you have no known sink for the human emissions and the ocean influx is too high in d13C to be the cause of the increase…
Ferdinand Engelbeen says:
July 24, 2012 at 3:28 pm
“With only 16 ppmv increase (or less, according to the solubility graphs) in the atmosphere, there is a decrease in CO2 inflow and an increase in CO2 outflow, sufficient to bring these two back into equilibrium, for a 1°C temperature increase, regardless of the initial deep ocean upwelling.”
A temperature rise decreases the outflow. As temperatures rise, the ocean releases CO2, so it carries less CO2 down. That creates an imbalance with what is upwelling, which is a quantity fixed hundreds of years ago by the conditions which prevailed when the water first downwelled. And, that imbalance integrates over time, so it builds up. And, that is why we have an integral relationship between temperature and CO2.
You do not know what the conditions under which the currently upwelling waters downwelled. You cannot even say when they downwelled with any precision. Whatever those conditions were, you are not going to match the upwelling with the same downwelling until equivalent conditions prevail today (and, I mean equivalent in the sense of partial pressures and temperatures which produce an equivalent downwelling). Since you cannot know these things, you cannot know what conditions are required today to establish equilibrium between the upflow and the downflow.
No matter how much you wave your arms, and claim to know the unknowable, the data indicate that we are nowhere near such an equilibrium.
“There is anyway a significant contribution of humanity, directly injected into the atmosphere, at twice the observed increase.”
Circulus in probando. You are begging the question.
“Any significant contribution from a natural process múst me compensated by a siginificant sink process that removes halve the human emissions + the natural contribution in total mass, or you are violating the overall mass balance.”
You do not have a complete inventory of the sinks and their capacities or their elasticity. If you recall, that was exactly an aspect of the problem which was being addressed by the article to which this thread is attached.
“But that mechanism is exactly what lacks in your formula.”
Not at all. It is quantified by the time constant tau in
dCO2/dt = -CO2/tau + K*(T – To)
The data inform us that tau is very large, so that limiting effects are not discernible in the ~54 year record we have available.
BTW,
“In all cases, the increase in the atmosphere reduces the oceanic releases (but can’t do that for human emissions or bacterial decay of vegetation) and increases the oceanic and land vegetation uptake.”
Here is a good English word for you: fungible. No matter the source, the oceans will be forced to absorb the same net CO2 from the atmospheric partial pressure increase, so it makes no difference. The sources are fungible, and you must treat them equivalently.