Guest Post by Willis Eschenbach [See updated graph]
Inspired by some comments on another thread, I decided to see what I could find in the way of actual measurements of the amount of CO2 in the surface layer of the ocean. I found the following data on the Scripps Institute web site. What they did was drive around the ocean on four different cruises, measuring both the atmospheric CO2 levels and at the same time, the amount of CO2 in the surface seawater. Figure 1 shows those results:
Figure 1. All air-ocean simultaneous measurements from four Scripps cruises are shown as blue dots. The horizontal axis shows sea surface temperature. The vertical axis shows the difference between the CO2 in the overlying air, and the CO2 in the water. The red line is a lowess curve through the data. The paper describing the Scripps data and methods is here.
Now, I have to say that those results were a big surprise to me.
The first surprise was that I was under the impression that there was some kind of close relationship between the atmospheric CO2, and the CO2 in the surface seawater. I expected their values to be within maybe 5 ppmv of each other. But in fact, many parts of the ocean are 50 ppmv lower than the CO2 concentration of the overlying air, and many other parts of the ocean have 50 ppmv or more of CO2 than the CO2 in the air above.
The second surprise was the change in not only the size but even in the sign of the trendline connecting temperature and CO2 (red line in Figure 1). Compared to the CO2 level in the air, below about 17°C the seawater CO2 decreases with increasing temperature, at a rate of about -2 ppmv per °C.
Above about 17°C, however, the seawater CO2 content relative to the air increases fairly rapidly with temperature, at about +4 ppmv per °C.
To describe the situation in another way, when the water is cool, it contains less CO2 than the overlying air … but when the water is warm, it has more CO2 than the overlying air.
Say what? I gotta confess, I have little in the way of explanations or comprehension of the reason for that pattern … all suggestions welcome.
w.
[UPDATE] By popular request, here is the same data, but in absolute rather than relative units and without the lowess curve.
Figure 2. As in Figure 1, but showing the CO2 content of the surface seawater directly. Atmospheric CO2 varied very little during the time of the measurements.
My main question in all of this is, how does the CO2 content of the seawater get to be up to 100 ppmv above the CO2 content of the overlying air? It seems to me that the driver must be biology … but I was born yesterday.
Regards,
w.
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“My main question in all of this is, how does the CO2 content of the seawater get to be up to 100 ppmv above the CO2 content of the overlying air? It seems to me that the driver must be biology … but I was born yesterday.”
Yes, that is an easy one = ‘It’s because of all the fish in the atmosphere breathing out’
It seems from the discussion above that the science is not settled—–even the means and method of measurement of something that at first blush seems elemental to any CO2-driven ocean/atmosphere temperature model are not settled. Just as Anthony Watts surface temps studies have shown, we do not even have reliable data to punch into our speculative and minimally scientific models. But apparently some can assert within a degree or two what global temps will be in a hundred years.
Willis,
The data you plotted are only a fraction of all the data sampled at a few fixed places over the past decades and from a lot of cruises all over the oceans, together with more recent buoys set out over the oceans (still sparce) comparing air pCO2 (~ppmv) with ocean surface pCO2.
The oldest data BTW were from a German research ship in the 1930’s, measuring pCO2 down to 2000 m depth…
The near three million measurements were used to compare CO2 in/out fluxes in different area’s of the oceans over the seasons and the net flux over a year. See:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/images/fig03.jpg
and
http://www.pmel.noaa.gov/pubs/outstand/feel2331/images/fig06.jpg
And the whole story about the measurements and calculations is here:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/abstract.shtml
The main reason that there are differences between ocean pCO2 and air pCO2 are:
– temperature
– biolife
– migration speed
The latter is the main problem: the migration speed of CO2 in water is very low. It is only by wind and waves that CO2 can exchange with the atmosphere at sufficient speed, depending mainly of wind speed. And at the same wind speed about in ratio with the pCO2 difference between air and seawater.
Thank you Anthony for being the beacon for those navigating in the treacherous waters of politicized science, Willis Eschenbach for this tantalising guest post and everyone contributing to the discussions. I cannot resist the temptation to build on ideas of Phlogiston, UnfrozenCavemanMD, Gary Pearse and others here.
If the sea mass is thousands times greater than the atmospheric mass, it seems hasty to build a earth encompassing hypothesis around a gas measured in parts per million in air – let along forecast anything based on it. There are other variables to identify and consider. Biosphere is a logical candidate and here is another:
Sea has an interface with an area we know less about than the surface of the moon. The Seven Sisters cliffs in Sussex hardly are the only natural chalk surface continuously eroded by the sea. They are made of relatively pure calcium carbonate (CaCO3). It is not very soluble in water, but dissolution increases when pH decreases.
CaCO3 + CO2 + H2O → Ca(HCO3)2
Because bicarbonate increases water alkalinity, CaCO3 dissolves more in cold than warm water. It precipitates (as limescale) when solutions are heated – releasing CO2 in the process.
Those green bands at the equator are driven by equatorial upwelling, cooler (a little), nutrient rich (and I presume CO2 rich) water brought to the surface by the Trade Winds and Ekman transport. Yes, there are plenty of phytoplankton that grow well up to 30 and even 35 C (or we wouldn’t have any in Chesapeake Bay in summer), but generally higher temperatures favor bacterial respiration over photosynthesis.
Thanks Willis interesting post. The third graph shows interesting patterns that seem replicated in part by the different cruises, strengthening the reality of their peculiarities.
The chlorophyll map is very interesting too. Australia’s Outback, N. Africa, the Andes and Rockies have an order of magnitude more chlorophyll than the equatorial and temperate zones. Surprised me that the ocean’s would be that sparse compared too these desert-like areas.
Willis Eschenbach says:
November 27, 2013 at 1:47 pm
there is plenty of chlorophyll in the “Pacific Warm Pool” around PNG and Indonesia.
Most biolife is where there is deep ocean upwelling: these bring a lot of nutritients to the surface, where shortage of minerals is the main constraint. See:
http://en.wikipedia.org/wiki/Upwelling
Another big problem in determining what all this means is that the term “sea surface” doesn’t seem to has a specific definition as to depth. With regard to CO2, the IPCC report considers the ocean surface to contain nearly twice the mass of CO2 as does the atmosphere while the intermediate depths contain more than fifty times the amount in the atmosphere. Very little of this surface ocean CO2 is transferred to the atmosphere, else the seasonal variations in CO2, as measured at Mauna Loa, would be much larger than is being recorded. These variations are due to the ocean area in the southern hemisphere being much larger that the northern hemisphere while atmospheric mixing is considered to be fairly rapid. This relatively small CO2 variation indicates very little of the available surface ocean CO2 is transferred between the ocean and the atmosphere, in turn, indicating that the ocean surface CO2 doesn’t change much as its temperature changes. When the seawater warms there is a significant surplus compared to equibrium, and conversely there is a significant shortage when it cools. The data Willis plots simply reflects this.
Apologies all, but I haven’t read the comments and they probably give the answer many times over: The system is not static, everything is moving. CO2 is emitted mainly by the warm tropics, travels to the high latitudes, and is mainly absorbed there. Then it goes into the deep and eventually goes round again. The atmospheric pCO2 (partial pressure) is lower than the ocean’s where the water is warm, because when water is warmed its pCO2 increases – hence the CO2 emission in the tropics. The CO2-depleted water travels to the high latitudes where it cools, hence its pCO2 decreases, hence it absorbs.
There’s an interesting quote at the start of the linked paper. One sometimes hears that AGW is just a scare rustled up by scientists after the ice age scare of the 1970’s failed. In fact, no ice age scare ever came from scientists. Lill and Revelle had it in 1958, IGY Bulletin:
“…Man, in his burning of fossil fuels and denudation of the land’s surface, may be performing a gigantic geochemical experiment in which the CO2 cycle is being influenced. It is thought we may be increasing the C02 input into the atmosphere by 70% in 40 years, although it is not certain how much of this may be absorbed by the oceans. A substantial increase in C02 content in the air would trap more of the earth’s radiated heat and cause a warming of temperature.”
Thanks for this post. Well, obviously someone forgot to take care of the exhaust from their speedboat. This report is bullshit. Someone got a nice trip paid in full with the taxpayer’s money. In that sense, it does not differ from all the other ‘scientific’ pollution from the alarmist camp. It has nothing to do with science, it tells us nothing, it disregards most scientific procedure, it costs a lot, and, as usual, it has nothing to do with reality. But people have been cooking temp. meters for some time, why not have a go at oceanic CO2. As we all know, from climategate, the saying goes: “What can we do to make people believe there is a crisis, when we can find nothing to indicate there is?” Let’s do another nature-trick.
I have no doubt some peer-reviewed guys will repeat this trip soon, and come up with almost identical results.
This also is a good review paper of the history of CO2 atmospheric research and the history of the IPCC shenanigans. The IPCC shenanigans very interesting, as noted the laws of physics change for CO2.
One of the key points is the resident times of CO2 in the atmosphere. The C14 bomb test analysis (Analysis of the spike of C14 produced by the atomic bomb tests) indicates the resident time for CO2 in the atmosphere is 7 years.) As the surface ocean reservoir is reversible (that is key) the only way C14 can drop to very, very low levels is there must either be mixing of deep ocean water with the surface water and/or C14 must precipitate out. If there is significant mixing of deep ocean water with surface water (this what the heat hiding in the deep ocean hypothesis requires) then the majority of the anthropogenic CO2 will be transferred into the deep ocean carbon reservoir which is more than 50 times greater than the atmospheric CO2 rise. The key logical point is that anthropogenic CO2 emissions are very, very, small compared to the super enormous, deep ocean carbon reservoir.
The physical implication of the C14 bomb test analysis is the majority of the CO2 increase in the last 70 years was caused by the warming of the oceans rather than the anthropogenic CO2 emissions. Truly fascinating!
http://folk.uio.no/tomvs/esef/ESEF3VO2.pdf
Carbon cycle modelling and the residence time of natural and anthropogenic atmospheric CO2: on the construction of the “Greenhouse Effect Global Warming” dogma. By Tom V. Segalstad: Suess (1955) estimated for 1953, based on the carbon-14 “Suess Effect” (dilution of the atmospheric CO2 with CO2 from burning of fossil fuel, void of carbon-14), “that the
worldwide contamination of the Earth’s atmosphere with artificial CO2 probably amounts
to less than 1 percent”. Revelle & Suess (1957) calculated on the basis of new carbon-
14 data that the amount of atmospheric “CO2 derived from industrial fuel combustion”
would be 1.73% for an atmospheric CO2 lifetime of 7 years, and 1.2% for a CO2 lifetime
of 5 years.
IPCC defines lifetime for CO2 as the time required for the atmosphere to adjust to a future equilibrium state if emissions change abruptly, and gives a lifetime of 50-200 years in parentheses (Houghton et al., 1990) (William: This is phony the number). Their footnote No. 4 to their Table 1.1 explains: “For each gas in the table, except CO2, the “lifetime” is defined here as the ratio of the atmospheric content to the total rate of removal. This time scale also characterizes the rate of adjustment of the atmospheric concentrations if the emission rates are changed abruptly. CO2 is a special case since it has no real sinks, but is merely circulated between various reservoirs (atmosphere, ocean, biota). The “lifetime” of CO2 given in the table is a rough indication of the time it would take for the CO2 concentration to adjust to changes in the emissions . . .”.
Lifetime of CO2 in the Atmosphere Based on bomb carbon-14 (in years)
Bien & Suess [1967]: >10
Münnich & Roether [1967]: 5.4
Nydal [1968]: 5-10
Young & Fairhall [1968]: 4-6
Rafter & O’Brian [1970]: 12
Machta (1972): 2
Broecker et al. [1980a]: 6.2-8.8
Stuiver [1980]: 6.8
Quay & Stuiver [1980]: 7.5
Delibrias [1980]: 6.0
Druffel & Suess [1983]: 12.5
Siegenthaler [1983]: 6.99-7.54
I misstated the IPCC report’s ocean CO2 in my previous post. Should read “the intermediate and lower depths contain more than 40 times the amount in the atmosphere”
Just a thought. Probably not relevant. But, Boyle’s law, Henry’s law, Charles’ law and Dalton’s law applied to scuba diving and gas are vitally important for the safety of divers.
“At a depth of 33 feet in the water, the pressure doubles, which means gas down there is compressed to half its volume. And every regular breath of air actually takes in twice as many air molecules as on the surface. That means the air in the tank only lasts half as long.
“Imagine taking a breath of air at a depth of 33 feet, then holding your breath and ascending to the surface. The air will expand to twice its size….” http://www.scubadiverinfo.com/2_physics.html
http://www.idc-guide.com/physics.html
Nick Stokes: “In fact, no ice age scare ever came from scientists. Lill and Revelle had it in 1958, IGY Bulletin:”
No ice age scare?
http://stevengoddard.wordpress.com/2013/05/21/the-1970s-ice-age-scare/
And, of course, all you’re stating by bringing up the ghost of Revelle is that we still haven’t empirically validated things 55 years later. An actual science might have run experiments at some point during this time. Odd
Willis, the source data contains lat/lon coordinates and these are very different among the four cruises. Plotting all the data together mixes different regimes. Biology most certainly affects the CO2 distribution. If you continue to investigate this, look into the spacial distribution of the data.
There’s CO2 in the ocean? Well, that answers the question of why the sea is boiling hot. Now for the one about pigs.
I downloaded the data for the Lusiad cruise from 1963 and simply plotted the CO2 data as a function of sequence number, which looks like it is just a continuous time record as the ship moved along its course. Now the CO2 levels decrease dramatically between row number about 1500 and row number about 2000, going down from about 370 to 270 CO2 units. I got curious to see what was going on there so I plotted the path the ship took in Lat Long using a web mapping tool and it seems during that time, the ship began in the middle of the Arabian Sea, worked its way over to the east coast of Africa, wound its way down the coast, passing between Madagascar and Africa proper, down around Cape Elizabeth, then back up the western coast a little then out into the Atlantic. The CO2 readings decrease steadily from up in the mid Arabian Sea down the coast until the ship rounded the Cape, then they began to rise steadily. Two obvious things could need to be considered. First, on the downward trip, the ship stayed quite close to the African coast on one hand and Madagascar on the other ( or port or starboard or something). For the downward leg, the ship seemed to be within 100 or 200 km of land, whereas once it turned the corner at the cape it appears to have headed out to the open sea, in excess of 500 km out.
Now I may have made a dumb mistake plotting the Lat Longs or something else but It seems a reasonable boat ride to take. An just looking at the changes in near shores and likely weather differences in the seas traversed, I think a lot more examination of the data is called for before anything useful could be obtained in terms of global climate and possible links between the global CO2 resident in the atmosphere versus the oceans in the large. A lot of local weather and oceanography would likely need to be taken into account. I will try to copy and paste my little Excel plot, but I am not sure if that works in a normal comment section.
If this works here is the plot:
Well it looks like I can’t copy and paste the plot. But it is a simple plot to do, just plot the CO2 levels versus the line (row) number (which turns out to be chronological order) and set the vertical axis minimum at around 250 or so to exclude the -999 cases.
I didn’t look at any other data, but this suggests to me that it will take a bit of close examination of the details of each cruise to try to get anything global.
Gary, at 4:49 PM, I just noticed your comment after I typed in my rather long one. I think I was just making your point with a little detail.
Fish farts and gut rocks and plants…
Ponds and fish tanks have wide swings with light and life for gasses and pH. Diffusion and solution are smaller…
Ferdinand Engelbeen says:
November 27, 2013 at 2:07 pm
That’s good info, Ferdinand, many thanks. I’m looking for the underlying data …
w.
It looks like the beginning of a fractal.
FWIW,
Might want to talk to the whales about where the food is, they probably don’t care what their food is eating as long as it sustains it long enough for the whale to find it.
Etc.
From Ferdinand Engelbeen’s citation, showing the pCO2 being both way above and way below the atmospheric level:
w.
I can see co2 gathering in the surface membrane in areas of outgassing. The warmer, the more outgassing, the more co2 in the surface.
Just like opening a bottle of coke, the co2 fizzes up, gathering at the surface as foam, before being absorbed into the the air.
Could be something similar going on here, perchance?