An impressive glacier formed from firn (FIRN), a Swiss-German word meaning “last year’s snow”. Note the clearly evident layers and, for a sense of scale, the people walking on the glacier, which is formed simply from fallen snow. Each distinct layer of firn contains a slightly different contribution from the atmosphere.
Here’s a thread to discuss the migration of gases (or not!) through firn, or old snow, and the ramifications for past levels of atmospheric gases. When I discover how to move comments between threads, I’ll add the relevant comments from other threads.
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Richard T, thanks for this although in my opinion the issue is centred on the ice lattice and not so much on firn or old snow i.e.next strata down (see my reply to Pete Ridley on this). Others may disagree of course.
I have emailed Tomoko Ikeda-Fukasawa, Associate Professor, Department of Industrial Chemistry, Meiji University, asking for an update on her work in this area since 2005 where she demonstrates by simulation that CO2 molecules diffuse a short distance (fraction of a nm) through the ice lattice.
She also found that CO2 molecules (and other gases) create their own pathway through the ice lattice by breaking the hydrogen bonds.
http://www.nanonet.go.jp/english/mailmag/2005/054b.html
This has huge implications for sampling and measurement of CO2 in ice cores if a proportion of CO2 molecules that were previously encapsulated in an air pocket that has been sampled have not been accounted for due to the diffusion.
Mike Palin is obviously not up to speed on this 5 year old research either.
Pete, in reply to your last March 21, 2011 at 11:26 am comment in the “It’s not warming thread”.
As you can see I have also emailed Tomoko Ikeda-Fukasawa although I suspect that after a 5 year time lapse she may have moved on to other fields or a different position and that her email address may not be valid now but I’ll give it some time. There are obviously more pressing issues in Tokyo right now too.
OK, I see that now although I’m not yet convinced that the cavities and pressure in the firn are sufficient to produce fractionation and migration at a sub-nanometer level i.e. you will have to expand or provide some reference material for your response:-
Huber et al 2006 deals with fractionation at the close-off level which is the firn/ice transition – not above. Above the close-off level, firn is porous allowing air (not the individual fractionated component gas molecules) to move freely, so although the diffusion is at a molecular level, the pores are not yet at sub-nanometer diameters. The sub-nanometer apertures are at close-off and below (Note that fractionation factor αi is calculated at close-off, page 65). If you can quote from the paper a specific reference to kinetic diameter apertures above close-off through which fractionated gases are passing, I will accede (i.e. “I think not” will not do).
My interpretation of Huber et al is that close-off is the most important zone because over time, that is the point where the air pocket capture (inclusion) takes place. If in the inclusion zone CO2 migrates more readily than other gas molecules then the air pocket is not a representative sample any longer but the reasons for the migration above close-off are gravity and thermal related and not by virtue of kinetic diameter sized pore aperture diameters. By “above close-off” I mean the level 50-70m below the surface (approx the last 20 years of the 400,000 year series but close-off rises over time maintaining the 50-70m distance).
Huber et al conclude:-
This is where I agree with your proposition. How can they conclude that close-off fractionation is nonexistent if they only consider collision diameter (page 65) and not kinetic diameter especially when they preface the conclusion with “Close-off fractionation factors for different gases depend strongly on the diameter”?
I disagree with your assessment of Severinghaus and Battle 2006. I see their reasoning but again I think you are interchanging “firn” and “ice lattice” erroneously. This quote:-
refers to the inclusion zone just above close-off where conditions of both ice lattice and firn exist but the pores (cavities, apertures) are considerably different. The sub-nanometer (collision – kinetic diameter) ice lattice apertures allow fractionation and make the ice lattice “slightly permeable to gases, with permeability being much higher for some gases than others” but that is not the case with firn in the inclusion zone because the apertures are larger (more porous).
I assume your bubble C is S&B’s B and your D is S&B’s C.
I think you’ve got it upside down. The highest compression is at A but the smallest apertures are between A and B therefore more smaller molecules will pass through the ice lattice wall (and diffuse in every other direction into the ice lattice). There are more and larger apertures between B and C (and in every other direction into the ice lattice) so that more and larger molecules are able to diffuse but the pressure is not as great so there is possibly less diffusion than from A to B. The model is over simplistic I think because there would be bubbles A-Z at least for any pressure difference to make any difference to aperture sizes.
The molecules are not being “squeezed up the ice sheet towards the surface” because the surface remains the same 50-70m distant (i.e. the close-off level rises as more snow is laid down) then bubble B becomes bubble A in the model and so forth. Each closed-off air bubble being slightly depleted of the smaller molecules (into the ice lattice as well as into other air pockets) and therefore unrepresentative of the original air sample but constantly so. It is in the more porous firn that air is being squeezed up towards the surface.
I was interested that Huber et al state “However, diffusion through ice is very slow (far less than 1 mm/yr)”. I would like to ask Tomoko to explain her simulation image. Over what time frame does it take place? The image seems to be a 2D depiction of a 3D event but what is the initial condition? An air pocket? A concentration of CO2 only? Is the pressure constant or increasing? Is the simulation applicable to real world gas diffusion in an ice lattice? The diffusion seems to meander through paths of least resistance rather than in any particular direction.
I’m inclined to think that the 83 year “correction” to ice core data is more significant than CO2 molecule depletion of ice core air pocket samples but would be interested to see how much depletion there actually is and what difference it would make to the Law Dome CO2 ppm dataset..
The “correction”:-
“CO2: The Greatest Scientific Scandal of Our Time”
by Zbigniew Jaworowski, M.D., Ph.D., D.Sc., March 2007
http://www.warwickhughes.com/icecore/
This is the dataset that ALL IPCC climate models use for initialization and subsequent simulations are based on, the results of which became the basis of govt policy.
Hi Richard C(umming?), thanks again for spending the time to put together such a well-considered response. I can’t understand why you draw such a sharp dividing line between firn and “solid” ice. I see the change as being a very slow one during which at a low enough level in the ice sheet there will co-exist “solid” ice, in which molecules migrate through the ice lattice, along with firn in which pores link air pockets. Some of the pores will be so small that not all of the different types of gas molecules in the air mixture can pass, allowing only the smallest ones through, including CO2, but preventing N2, O2 and CH4. Other pores will be large enough for the whole air mixture to diffuse. I also hypothesise that both Fickian and Knudsen diffusion takes place, depending upon the size of those pores, with Fickian being relevant in the upper layers of firn and Knudsen at the approach to “complete” close-off and a gradual shift in emphasis down the ice sheet.
If that notion is flawed then it should be easy to show how.
I have sent another E-mail to Professor Fukazawa mentioning you and including a copy of my latest comment. I included Professor Severinghaus in the loop because of the relevance of the Severinghaus & Battle papers and the Huber paper which he co-authored. If you’d like sight of my E-mail and wish to be included I any further exchanges then please let me have an E-mail address (or ask Professor Fukazawa if she’d mind passing it on to me).
I’ll respond to your latest comment in more detail after I have attended to the chores that my wife has listed for me.
Best regards, Pete Ridley
The sharp distinction as I understand is the close-off level, Below that is impermeable ice but Prof Ikeda-Fukasawa’s work seems to show that diffusion takes place over a limited area (approx 1.25nm x 1.25nm). Immediately above that level is the inclusion zone where as you say ice and firn coexist (Fig 1 page 63).
The crystalline ice lattice is clearly defined for ice in the inclusion zone and below. Huber et al show a diagram (Fig 10 page 71) with annotation describing the dimensions of the hexametric box. in angstrom units (0.1 nm). The a x b axis dimensions are 4.511 Å x 4.511 Å (0.4511 nm x 0.4511 nm) but the distance between oxygen atoms is 0.275 nm leaving a 0.275 nm x 0.275 nm square aperture further obstructed by the hydrogen atoms. This means that a CO2 molecule must break the hydrogen bonds AND distort the structure to pass the a x b aperture (vertical direction) whether either 0.33 nm dia or 0.36 nm dia is assumed. In view of this mechanism, it is immaterial what CO2 dia is adopted because the CO2 molecule creates it’s own pathway anyway i.e. it’s not a sieving mechanism but a bond breaking and structure distorting mechanism that allows CO2 to pass, diffuse or migrate..
So that’s the ice situation. Now I repeat my challenge for you to reference a diagram or quote from Huber et al, S&B or any other paper that defines firn in a similar way. You will have to show aperture dimensions in angstroms or nm and demonstrate that CO2 can pass but the larger molecules cannot. I wont accept hand waving but will accede if you can prove this assertion:-
So far you have not supported the assertion with dimensioned diagrams or quotes from any papers and until you can your assertion has no validity i.e the flaw in the notion is that you have not supported it with any detail. I’ve supported and detailed the ice situation, now I want to see the same for firn with an explanation of the mechanism (bond breaking, structure distortion, molecular sieving etc). Given that firn is porous, the dimensions involved for firn will be considerably larger than ice so you will have to provide convincing evidence of the mechanism you describe.
I suspect that we may have to contact the Department of Industrial Chemistry, Meiji University to find out if Prof Ikeda-Fukasawa’s work in this field has been progressed by her or anyone else over the last 5 years and what are the contact addresses (and can we communicate in English). The email address I found may not be Tomoko’s current contact. I have emailed her myself and provided links to both this forum and the previous thread.
Rich.
“ice and firn coexist (Fig 1 page 63).” – this reference is to Huber et al sorry.
This is the contact page for Meiji University, Department of Industrial Chemistry last updated 23/8/2008
http://www.isc.meiji.ac.jp/~chem/index-e.html
Tomoko Fukusawa’s latest address is:- fukazawaÅEisc.meiji.ac.jp
I have used an invalid address I think :- fukazawa@isc.meiji.ac.jp
I’ll try again using the 2008 address.
This email went somewhere:- fukazawa@Eisc.meiji.ac.jp
Nope.
Delivery to the following recipient failed permanently:
fukazawa@Eisc.meiji.ac.jp
Technical details of permanent failure:
DNS Error: Domain name not found
I didn’t get this message using fukazawa@isc.meiji.ac.jp but I haven’t received a response yet.
Effects of molecular diffusion on trapped gas composition in polar ice cores
Ikeda-Fukazawa, T | Fukumizu, K | Kawamura, K | Aoki, S | Nakazawa, T | Hondoh, T
Earth and Planetary Science Letters. Vol. 229, no. 3-4, pp. 183-192. Jan. 2005
Enrichment of nitrogen gas has been found from gas analyses of ice cores retrieved from deep parts of Antarctica. Neither climate change nor gas loss through ice cracks explain the enrichment. In order to investigate the mechanism of the gas composition change, we develop a model of gas loss caused by molecular diffusion from clathrate hydrates toward the ice-core surface through ice crystal. We apply the model to interpret the data on the gas composition change in the Dome Fuji ice core during the storage for 3 years at 248 K. The mass transfer coefficients determined using the model are 1.4×10-9 and 4.3×10-9 m;s-1 at 248 K for N2 and O2, respectively. The difference in the coefficient between N2 and O2 causes the change in the O2/N2 ratio of the trapped gas in the ice core during the storage. During the storage period of 1000 days at 248 K, the O2/N2 ratio changes from-9.9 to-20.5. The effect of the gas loss decreases as the storage temperature decreases. The results have important implications for the accurate reconstructions of the paleo-atmosphere from polar ice cores.
http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=A054258121AH&q=&uid=790522361&setcookie=yes
—————————————————————————————————————————–
They are are using an ice core that has been removed from the drill hole (so it is not subject to pressure) and the gas migration is towards the outer surface of the core. So diffusion seems to be along paths of least resistance in ice i.e pressure is not the driver.
Both Huber et al and Severinghaus and Battle conclude a 36nm limit for fractionation (excluding CO2 with collision diameter 39nm) but Ikeda-Fukusawa et al don’t seem to apply the same constraint and show CO2 fractionation and diffusion through the ice lattice.
Someone has got it wrong.
Huber et al are unsure in their conclusion:-
If CO2 diffuses through the ice lattice as Ikeda-Fukusawa et al demonstrate, then the 36nm limit is an erroneous conclusion.
3-D Snow and Ice Images by X-ray Microtomography
ESRF Newsletter No 35: June 2001
Results on firn and ice
Fig. 3: 2- and 3-dimensional images of ice around the firn-ice transition: porosities appear in black in the 2-D images. The episcopy technique reveals that the pores are located at crystal boundaries. 3-D reconstructions from the 2-D slices give access to the real shape of the porosities.
http://www.esrf.eu/info/science/newsletter/jun01/snow.html#fig3
Pete, note that the 3D porosities are shown in a 3mm x 3mm cube. This demonstrates that the pore dimensions for firn (even at the transition zone) are measured in fractions of a mm (as opposed to fractions of a nm for ice) and that air is relatively free to move unhindered through the pores without fractionation into constituent gases above the transition (inclusion) zone.
Also this diagram showing the porosity of firn at 0.1m depth, 1m, 10m, 70m and 80m. Firm is very porous down to the top of the inclusion zone (70m in the diagram) allowing movement of air so that the sub-nanometer dimensions of air molecules are irrelevant over the first approx 70m range of firn. The sub-nanometer molecular dimensions only become critical once the firn crystallizes to ice.
http://xtide.ldeo.columbia.edu/mpa/Clim-Wat/Climate/slides/firn.gif
Hi again Richard (C), I haven’t finished wading through your earlier comments but thought it best to keep abreast of your latest comments in case they change my responses. I appreciate how you are getting your teeth into this and you are helping me enormously to firm up my own ideas. Why can’t the supporters of the CACC doctrine approach the exchange of opinions on this issue in the same manner.
First a typo correction. In your comment of March 22 at 4:18 pm you said 36 and 39nm instead of 0.36 & 0.39. Although you and I know what you meant others could be misled.
Thanks for the links in your comment of March 22 at 7:26 pm to “3-D Snow and Ice Images by X-ray Microtomography” (http://www.esrf.eu/info/science/newsletter/jun01/snow.html#fig3) and the diagrammatic representation of progression of snow to firn to ice (http://xtide.ldeo.columbia.edu/mpa/Clim-Wat/Climate/slides/firn.gif) which presents a far clearer picture of what I was trying to describe in my previous comment. This comment is noteworthy “The transformation of the snow into ice can be very slow in polar regions (up to 3000 years) and it is very important to know precisely when and how the gas was trapped in order to interpret the air archive (atmospheric information)”.
What you said is in agreement with my comments earlier that there is a change in the migration process from top to bottom. I don’t accept that “eyeballing” Fig. 3 gives a clear understanding of the structure of the pores and interconnecting channels at the nm level. I also have a suspicion that when the authors talk about “pores” they are referring to what I call “air pockets”. They say “3-D reconstructions from the 2-D slices give access to the real shape of the porosities” but I can only get an idea of the shapes of air pockets. I see no justification for your conclusion that “The sub-nanometer molecular dimensions only become critical once the firn crystallizes to ice”.
Best regards, Pete Ridley
Visualization must be in the context of the dimensions involved. 1 millimetre = 1×10^-3m or 1/1000th of a metre. 1 nanometre = 1×10^-9m or 1/1000,000,000th of a metre. “Pores” are in the millimetre dimension and describe interconnected cavities in firn i.e. they are a characteristic of firn hence the description of firn as “porous” with high “porosity” applicable over the top 70m down as far as the top of the inclusion zone. Below 70m (in the inclusion zone) the firn changes phase to ice and the previous characteristics are no longer applicable once firn has changed to ice. The ice crystalline structure is in the nanometre dimension and describes atomic bonds and molecular arrangement relative to other molecules. At the close-off horizon the transition from firn to ice (change of phase) is complete so that the resulting mass is “solid”.
No, definitely not. “Pores” are the interconnected cavities (including larger “air pockets”). “Close-off” is the process that compresses the smaller pores leaving the larger air pockets sealed off with the air trapped. Prior to close-off, the air is free to move through the porous interconnections and near the surface there is even a degree of firm/atmosphere air coupling.
Try visualizing large cavities (air pockets) interconnected with other large cavities by smaller cavities (pores) similar to an underground cave system that speleologists explore. Then look at the 3D graphic the same way.
The specific definitions are:-
Ice: Is the solid form of water. The phase transition occurs when liquid water is cooled below 0 °C (273.15 K, 32 °F) at standard atmospheric pressure. Ice can be formed at higher temperatures in pressurized environments, and water will remain a liquid or gas until -30 °C at lower pressures. Ice formed at high pressure has a different crystal structure and density than ordinary ice.
Everyday ice and snow is ice Ih, or hexagonal ice. Subjected to higher pressures and varying temperatures, ice can form in roughly a dozen different phases. Only a little less stable (metastable) than Ih is cubic structure ice (Ic). But cooling Ih causes a different arrangement to form in which the protons move, XI.
With both cooling and pressure more types exist, each being created depending on the phase diagram of ice. These are II, III, V, VI, VII, VIII, IX, and X. With care all these types can be recovered at ambient pressure. The types are differentiated by their crystalline structure, ordering and density. There are also two metastable phases of ice under pressure, both fully hydrogen disordered, these are IV and XII. Ice XII was discovered in 1996.
Clathrate hydrates are forms of ice that contain gas molecules trapped within its crystal lattice. [The subject of the Ideka-Fukusawa et al simulations]
http://www.wordiq.com/definition/Ice
Firn: Material transitional between snow and glacier ice; it is formed from snow after existing through one summer melt season and becomes glacier ice when its permeability to liquid water drops to zero. Also known as firn snow.
http://encyclopedia2.thefreedictionary.com/firn
Granular, partially consolidated snow that has passed through one summer melt season but is not yet glacial ice. Also called old snow.
http://www.answers.com/topic/firn
Summary for ice:- Solid, nanometer measurement units, impermeable.
Summary for firn:- Partially consolidated snow, millimetre measurement units, porous.
Therefore, the sub-nanometre molecular dimensions only become critical once the firn crystallizes to ice
The “previous comment” to which I refer in the above comment was submitted about an hour ago but has not yet appeared, perhaps because of the numerous links that I included, so I repeat it here without some of the links and will send the remainder separately.
Hi Richard (Threadgold), may I offer a belated thank-you for setting this up as a separate discussion thread.
Hi Richard (C), you say “ .. I’m not yet convinced that the cavities and pressure in the firn are sufficient to produce fractionation and migration at a sub-nanometer level i.e. you will have to expand or provide some reference material for your response”. I do not understand why you are unable to envisage air molecules having kinetic diameters greater than around 0.33nm (e.g. N2, O2, Ar, CH4) being unable to pass through pores and channels in firn that are 0.33nm in diameter (the kinetic diameter of CO2).
The simplistic ice sheet profile from top to bottom starts off with the highly open porous structure of the accumulated falling snow (NOTE 1) with a low density “New snowfall is typically between 7% and 12% but can be lower or higher than this sometimes. Wind exposure often increases the density to 20% to 30%” (Note 2). It ends up at the bottom as almost solid ice with some air pockets, fissures and cracks (Note 3). In other words, as shown in Huber et al. (http://icebubbles.ucsd.edu/Publications/Huber_closeoff_EPSL2006.pdf) Fig. 1, there is a structure progression from a highly porous “sponge” to almost solid block. Migration of air within this structure involves changing processes, from Fickian diffusion when the pores and channels are large in diameter, to Knudsen diffusion/effusion and Poiseuille diffusion when they approach the size of the molecules themselves.
Dr. Keith Murphy of the Get Nitrogen™ Institute, Denver, Colorado 80211 gives a helpful explanation of the significance of kinetic diameter when considering molecular permeation through a porous medium when the passageways are of similar size to the molecules themselves. He also describes the fundamental difference between permeation, effusion and diffusion (http://www.getnitrogen.org/pdf/graham.pdf). The comments that he makes are specifically addressing N2 v O2 but apply just as well to other air molecules.
Huber et al. in Section 5 say “ ..we favor an explanation by diffusion through the ice matrix .. ” and are focussing their analysis on one possible migration process through the structure of one type of perfectly formed ice crytal, as depicted in Fig 10 page 71. You say “ .. it’s not a sieving mechanism but a bond breaking and structure distorting mechanism that allows CO2 to pass .. ”. I do not reject this as being another of the migration mechanisms within the ice sheet and said so on the “It’s Not Warming You Nitwit” thread (March 16 at 7:34 am). The perfect ice crystal is not the structure that I am giving consideration to or have any particular interest in at this stage. My interest in ice is as an air-filled “sponge” from the time that it forms as snow through to compression into firn before it becomes a block of ice (not even then a perfect ice crystal). If you are interested in ice crystals you may find “Ice Structure” by Steven Dutch, University of Wisconsin, worth looking at (Note 4).
Huber et al. go on to say “ .. a critical size of 3.6 Å implies diffusion through channels of about the same dimension .. an outlet from a closing bubble .. changes its dimension steadily from open to closed. .. Diffusion coefficients of gases in ice show a size dependence similar to our findings beside for Ar and O2 .. ”. They should have included CO2 along with those two but didn’t because (I believe) they were focussing on the close-off fractionation of other gases and were misled into ignoring CO2 through using collision not kinetic diameter.
My head is starting to hurt now so I’ll have to go for now but I see that you have been doing a lot more research and it all looks very interesting. I’ll be back.
BTW, I used this address for Professor Fukazawa and await a response too fukazawa@isc.meiji.ac.jp
I cannot envisage it simply because the pores and channels in firn are in the millimetre dimension – not the nanometer dimension (see my explanation upthread).
This is not relevant because the process is diffusion of AIR – not fractionated constituent gases. Yes, different gases will diffuse at different rates but it is still within an air mass. As I understand, O2 will diffuse 22x faster than CO2 so if anything, CO2 s a laggard.
This is where you have got it very wrong. Please see the definitions of “Ice” and “Firn” upthread. There are 3 distinct “zones”:-
1). The upper 70m approx. of firn (very porous, sub-millimetre).
2). The intermediate 5-10m approx. inclusion zone (transition of porous firn, sub-millimetre to impermeable ice, sub-nanometre).
Close-off at approx 80m
3). Solid ice.
You need to differentiate strictly in terms of the different types of ice (snow and firn are types of ice) and the characteristics and dimensions of each type.
I repeat, sub-nanometre distances do NOT become critical until the inclusion zone 2) and even then NOT until the crystalline structure (lattice, matrix) of solid ice forms. That is why Huber et al. “favor an explanation by diffusion through the ice matrix”.
This is where I agree with you although I subscribe to Ikeda-Fukusawa et al at this point because 36nm is not necessarily the constraint. Huber et al are treating the mechanism as a simple sieve process but Ikeda-Fukusawa et al indicate that it is not and that a CO2 molecule may pass an aperture of indeterminate size because it creates its own pathway by breaking the hydrogen bonds and distorting the ice matrix (lattice). Repeating (and correcting) my previous comment:-
The simulation of Ikeda-Fukusawa et al has CO2 passing through a 0.275 nm x 0.275 nm square oxygen matrix further obstructed by the hydrogen atoms, the diagonal distance between oxygen atoms being 0.389nm. If the lattice is distorted in the process (and hydrogen bonds broken), the constraint becomes larger than 0.389nm. Adoption of a CO2 molecular diameter of less than 0.39nm is not really necessary but if 0.33nm is used, the obstruction is only the hydrogen atoms and lattice distortion is unnecessary for the CO2 molecule to pass.
I get the impression that the Japanese are more certain and more at home in the nano-zone of the study than are Huber et al or S&B, I just wish I could get hold of the full Ikeda-Fukusawa et al paper.
NOTES:
1) see http://www.its.caltech.edu/~atomic/publist/rpp5_4_R03.pdf
2) see http://www.avalanche-center.org/Education/glossary/density.php
3) see http://www.123rf.com/photo_8520324_macro-of-ice-structure-with-air-bubble.html
4) see http://www.uwgb.edu/dutchs/Petrology/Ice%20Structure.HTM
Best regards, Pete Ridley
The issue of air molecule migration within the “solid” ice lattice after close-off is summarised in “Effects of Molecular Diffusion on Paleo-atmospheric Reconstruction from Polar Ice Core” by Tomoko Ikeda- Fukazawa and Takeo Hondoh (http://wwwice.lowtem.hokudai.ac.jp/project/abstracts.pdf” (listing 7 references by Fukazawa. They say “ .. the air molecules hop in the crystal by breaking hydrogen bonds in the ice lattice. The diffusion velocity with the breaking bond mechanism (BBM) is few orders larger than the estimate under the assumption of the interstitial mechanism”. I have no disagreement with your “ .. This means that a CO2 molecule must break the hydrogen bonds AND distort the structure to pass the a x b aperture (vertical direction) whether either 0.33 nm dia or 0.36 nm dia is assumed. In view of this mechanism, it is immaterial what CO2 dia is adopted because the CO2 molecule creates it’s own pathway anyway i.e. it’s not a sieving mechanism but a bond breaking and structure distorting mechanism that allows CO2 to pass, diffuse or migrate.. So that’s the ice situation. .. ” – but I’m interested in the situation in firn, not ice.
On March 21 at 4:32pm you say that “I disagree with your assessment of Severinghaus and Battle 2006. I see their reasoning but again I think you are interchanging “firn” and “ice lattice” erroneously .. ”. In my simplified model I consider the ice sheet vertical profile as comprising two zones:
– the upper (firn) comprising air surrounded by “pockets” within the snow “fabric” having pores connecting to channels between other pores and pockets, with the size of pockets, pores and channels decreasing in size down the profile towards
– the lower (“solid” ice) comprising isolated air pockets within bulk ice.
The ESRF 3D reconstructions in Fig. 3 (http://www.esrf.eu/info/science/newsletter/jun01/snow.html#fig3) appear to me to show this structure quite clearly, with the surface of the blue air pockets covered in tiny pores
The diagrammatic representation in (http://xtide.ldeo.columbia.edu/mpa/Clim-Wat/Climate/slides/firn.gif) suggests a different structure, with the air pockets simply being remnants of the firn’s air circulation channels, for which I see no justification.
I haven’t drawn a specific distinction within the firn as it transits into the “solid” ice state, nor have I given any attention to the Winter/Summer layering depicted in their Fig. 1. Perhaps this is why you think that I am confusing firn with what you call “lattice ice”. The Severinghaus and Battle paper is not in conflict with my simple model, since “ .. the firn–ice transition region where bubbles are closing off .. ” to which they refer has to exist. Their paper seems to me to be quite clear about what they are referring to and says “The model presumes that fractionation is caused by selective permeation of gas through the ice lattice from slightly overpressured bubbles .. Here we concentrate on a third process that alters firn and bubble air composition: the preferential exclusion of Ne, Ar and O2 during bubble close-off”. They are not talking about after close-off but during it.
Their Fig. 1 provides a reasonable representation of the size-dependent fractionation process for O2 and Ne, although they appear to be thinking purely in terms of pocket, pore and channel reduction due to the change in snow density arising from increasing winter cold. Although I can see that NH ice sheets could experience significant changes due to seasonal differences I am dubious about how relevant that is for most of the Antarctic, which is so much colder (any ideas?). A better representation would show with one winter layer sandwiched between two summer ones instead of simply one half of a winter atop a summer. If you imagine that part of Fig. 1 turned upside down then that is a reasonable representation of what I hypothesize happens as a result of increasing firn density arising from increasing compression. Regardless of how that reduction in pore and channel size occurs, the size-dependent fractionation process will still take place.
Table 1 shows molecular “ .. diameter .. ” for 12 air components and the “Observed Fractionation from N2 .. ” but makes the error of using collision rather than the correct kinetic diameter measure (Dr. Murphy, Get Nitrogen Institute, in http://www.getnitrogen.org/pdf/graham.pdf).
Huber et al. (http://icebubbles.ucsd.edu/Publications/Huber_closeoff_EPSL2006.pdf)acknowledge the scientific uncertainties about the mechanisms involved in the migration of gas molecules within the ice of an ice sheet at this critical stage approaching close-off. In Section 5, after describing the possible processes, they conclude “The critical size of about 3.6 Å seems to be an upper limit up to which molecules fractionate during the close-off process in the firn. A possible explanation for this could be the diffusion of molecules through channels in the ice lattice. From our findings we believe that the effect of close-off fractionation is nonexistent or at least very small for isotope ratios and for large molecules, like Xe, Kr, N2, CO2, CH4, and N2O. This is an important confirmation for the integrity of polar ice cores as a climate archive of the ancient atmospheric composition of these gases.” I challenge their inclusion of CO2 among those gases. CO2 should be among the excluded gases along with Ar, He and Ne because all have kinetic diameters less than the magic 0.36nm. I believe that they misled themselves as did Severinghaus and Battle by considering only collision diameter.
As an aside, while searching for details of the kinetic diameter of Ar I came across another set of similar graphs for He, Ne, CO2, Ar, O2, N2 (http://www.gsi.de/documents/DOC-2006-Mar-55-1.pdf Page 11) which again shows that there is a significant turning point in size-dependent selectivity around a kinetic diamter of about 0.375nm. They also show the membranes CO2 having a significantly greater selectivity than O2 or Ar and even more so over N2. I’m not drawing any parallels here with the processes with an ice sheet, just drawing attention to that significant matter of kinetic diameter and the importance of the 0.36nm mentioned by Severinghaus.
That’s enough for now.
Best regards, Pete Ridley
I think I’ve addressed all the points we agree and disagree on so it’s probably productive to move on. I have to say though, that I don’t think you will engender credibility by persisting with your notion of sub-nanometer criticality in firn which you have not yet proved BTW.
You will have to because they have entirely different characteristics and applicable measurement units – porous and sub-millimetre for firm, impermeable and sub-nanometre for solid ice.
The issue in the bigger picture is that the ice core air pockets that have been sampled seem to be depleted of the smaller molecule gases including CO2, but by what factor for each?
Law Dome – Carbon Dioxide Data
http://www.ncdc.noaa.gov/paleo/metadata/noaa-icecore-2455.html
Historical CO2 record from the Law Dome DE08, DE08-2, and DSS ice cores
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/law/law_co2.txt
1900 296.7
1905 298.2
1910 299.9
1915 301.5
1920 303.2
1925 304.9
1930 306.5
1935 308.0
1940 309.3
1945 310.5
1950 312.0
1955 314.1
1960 316.9
1965 320.5
1970 324.7
1975 329.4
This series is then spliced to Mauna Loa data to provide the CO2 initialization parameters for computer simulations. By what factor should the values be increased? 1.01? 1.1? 1.5?
We already have the controversial “adjustment” to rectify the age-of-ice/age-of-air discrepancy that was unable to be scientifically justified along with the splice of disparate ice core sample – air sample datasets. Now who is going to prove that the ppm values are not reducing with time simply because the molecules have been leaching out of the air pockets into the surrounding ice lattice and how are they going to do that?
What a bogus dataset.
“By what factor should the values be increased? 1.01? 1.1? 1.5?”
It would make even more sense if the factor was increased with time e.g.
1975 329.4 x 1.01
1935 308.0 x 1.05
1900 296.7 x 1.1
Hi Richard (C), it seems that you would prefer to drop the discussion on kinetic v collision diameter wrt molecular migration through firn and pursue another of Professor Zbiniew Jaworowski’s concerns, the air-ice-age difference estimates. This is another of several areas of uncertainty about the processes that can distort the attempts to reconstruct past atmospheric CO2 concentration from air “trapped” in ice for millennia.
These different physio-chemical processes apply from the very start with the formation of snow. I said in my March 16 at 11:37 pm comment on the “It’s Not Warming You Nitwit .. “ thread (https://www.climateconversation.org.nz/2011/03/its-not-warming-you-nitwit-its-cooling/#comment-45360) “ .. Professor Hartmut Frank wrote a forward to Jaworowski’s 1994 paper .. ”. In June Frank confirmed his support for Jaworowski, saying “ .. Jaworowski’s main argument is valid and will remain valid because it is based on simple, but hard physicochemical facts”. To that E-mail he attached a slide (from one of his recent presentations to graduates at Technical University in Gdansk) which he described as “ .. a simplified illustration of the major processes which are leading to changes of gas concentrations in the secondary bubbles (including and especially of carbon dioxide) .. ”. It discusses the manner in which atmospheric air collected within the voids of forming snow has already been depleted in CO2 before it even hits the top of the ice sheet.
I don’t know how to embed a pdf page into this comment so will have to describe it (if you’d like a copy then send me an E-mail and I’ll attach it). The slide provides a diagram showing falling snow beneath which is the section of a fully developed ice sheet. Alongside it says “Assuming a specific weight of 1 dm3 snow as 0.1 kg/L, it consists of 10 Vol-% of snow-ice and 90 Vol-% of air. Thus, a dm3 snow may contain a total carbon dioxide content of which 4 mg is adsorbed and 0.54 mg comes from the air between the snow flakes –explaining the high values found in ice cores by the gas extraction over long time in the molten state”.
It then goes on to summarise the snow/firn/ice compaction stages after “Deposition:
– Compaction to firn, air bubble closure (when?),
– Chlathrate formation (CO2~ 5 atm) [CO2•5 H2O] preferred diffusion of CO2 into the ice matrix
– Chlathrate formation (N2, O2at ~ 20 atm)
– Carbonic acid formation (formulae shown) N2, O2 non-reactive: selective depletion of CO2
– Primary bubbles disappear.
– Upon drilling and horizontal storage of ice cores, expansion and back diffusion of N2, O2 and CO2 (and slow decomposition of carbonic acid) into secondary bubbles occurs, at different rates”.
I see no conflict there with the picture that I have presented on these two threads when discussing “Another Hockey Stick Illusion?”, even though it makes no reference to the process that I am concentrating on at the moment, which remains unresolved. Some disagreements between us remain to be resolved, especially your insistence that size-dependent fractionation occurs exclusively through individual molecules breaking H-bonds within the ice crystal. I recognise this as another of the several processes that take place in the ice it is not the cause of the preferential fractionation gases having of smaller kinetic diameters that N2, O2, Ar or CH4.
It is fundamental to my hypothesis that at a late stage in the compression of firn gas molecules migrate through pores in air pockets which allow the smaller gas molecules to leave the pocket and enter interconnecting channels between pockets but prohibits the escape of larger molecules. I shall expand on this in a later submission by following the ice sheet development process from snow through firn to ice.
Best regards, Pete Ridley.
Whatever progress we make here will not change the fact that the Law Dome dataset CO2 ppm values are the accepted means of providing pre 1975 data for all the IPCC climate model simulations. There’s a mountain of results that have been churned out of supercomputers using Law Dome initialization but all the focus is on the output – not the input.
What we and others are discovering is the uncertainty of the pre-1975 CO2 initialization data but what is the range? At this point I have no idea. The revelation is that this uncertainty has been evident for at least the last 17 years but it is not public knowledge and neither is the recent work. When the various issues are brought together it paints a very unflattering picture but the vested interests will do their utmost to maintain the status quo.
Our aim should be I think to just list the uncertainties in a simple bullet point paragraph otherwise all that happens is that screeds of ineffectual writing is exchanged but for what?
Re your hypothesis.
You have completely ignored my challenge for you to provide proof of sub-nanometer criticality in firn (i.e. the pore dimensions). Until you do it is a null hypothesis for firn as far as I am concerned.
I have produced a graphic (3-D Snow and Ice Images by X-ray Microtomography) that clearly shows firn pores are in the sub-millimetre dimension (not sub-nanometre). I’m still waiting for you to produce a similar graphic supporting your sub-nanometer criticality for firm. I am 99.99% sure that the reason for that is because the evidence does not exist.
I do agree that 36nm is not necessarily the constraint in solid ice and that the 39nm collision diameter adopted for CO2 must be incorrect. Given that I subscribe to the bond breaking lattice distorting mechanism of Ideka-Fukusawa et al, I don’t think a specific diameter is applicable because a molecule is nothing like a perfect sphere and the respective kinetic/collision diameters are little more than nominal values. The CO2 molecule either passes through the ice lattice or it doesn’t and the papers we have looked at indicate that it does.
Rich
Looking at the definitions I can find, Collision diameter is not even applicable to a molecule passing an aperture:-
Collision diameter: the distance between the centers of two colliding molecules when at their closest point of approach.
http://dictionary.reference.com/browse/collision+diameter
Kinectic diameter: the diameter of a pore needed to let that specific molecule pass.
http://www.patentstorm.us/patents/7214719/description.html
Even the kinetic diameter is pore size – not molecule size, but it is the relevant constraint. Collision is another process entirely.
Kinetic diameter then (or thereabouts), is the applicable constraint for molecules passing through a solid ice matrix (lattice).
Mike, what I hear you saying when you reject size-dependent migration within the deep firn of the smaller atmospheric gases like CO2 and He is that at some stage in the compression of the firn there is a quantum drop in the size of the pores or channels. You appear to be saying that before this point all gases can move out of the air pockets and along channels (relatively) freely but afterwards none can migrate other than by forcing their way through the solid ice through H-bond breaking. To lay people like us this is counter-intuitive therefore you must have come across some evidence that such a quantum drop happens as you appear to suggest. I don’t recall you pointing to any such evidence during our exchanges so I must have missed it. Please would you say again how do you justify such an opinion.
My hypothesis is based upon there being a continuous reduction in pore and channel size through compression (and possibly also by adsorption on their surfaces, particularly of CO2, but that is another process for later consideration) until any particular pore is completely closed off to all air components.
There is an excellent simple diagrammatic representation of an ice sheet vertical profile in the University of Copenhagen’s Centre for Ice and Climate article “The firn zone: Transforming snow to ice ” (http://www.iceandclimate.nbi.ku.dk/research/drill_analysing/cutting_and_analysing_ice_cores/analysing_gasses/firn_zone/) which I shall use in my explanation.
My starting point is to show that the air pockets with pores into channels that connect between pockets do form, are compressed and at some stage become isolated from one another. That involves a review of the structure of falling snow. A snow flake starts as a tiny lump of ice around a spec of dust http://www.its.caltech.edu/~atomic/snowcrystals/faqs/faqs.htm), initially developing as solid ice crystals with no air pockets. “A Guide to Snowflakes” (http://www.its.caltech.edu/~atomic/snowcrystals/class/class.htm) takes a look at the form of these crystals and how the many different snow flakes are formed from the same basic building block (which itself is not perfectly smooth). As the flake develops an open network of branches forms which surrounds air, i.e. linked air pockets are formed within the flake as it grows, resulting in a “fluff-ball” which is up to 90% air within a fabric of only 10% ice.
The second stage is the gradual compression of layers of snowflakes, crushing the open structure of hexagonal ice building blocks (but not the blocks themselves) and conversion first to firn then to ice. In his “Glaciers” article (http://people.hofstra.edu/j_b_bennington/33notes/glaciers.html) geologist Dr. J Bret Bennington, a Professor of Geology at Hofstra University, NYC said “Formation of glacial ice: Glacial ice begins as snow, which has high porosity and low density (.07 – .18 g/cc). Snow that survives the summer season undergoes a progressive transformation into more compact granules and finally into ice crystals. As the snow becomes buried under successive seasons of new snow it compacts and the crystals melt at grain-grain contacts. Melt pore water flows into empty spaces and re-freezes. The material near the surface of a glacier has a density from .4 to .8 g/cc and is known as firn or neve. This transformation can take from days to years, depending on the frequency and severity of freeze-thaw cycles. With further compaction and recrystallization the firn reaches a density of .8 – .9 g/cc and becomes ice. This final process can take years in temperate glaciers or hundreds to thousands of years in polar glaciers.” (http://www.teachmefinance.com/Scientific_Terms/Firn_Snow.html).
Throughout this compression arising from the increasing weight of snow above each air pocket, each pore in them and each channels linking pockets reduce steadily in size (no sudden drop and not all simultaneously) until eventually all pores are closed to all air components. As this gradual closure takes place a stage is reached where molecular size becomes relevant and the escape routes for the larger molecules (N2, O2, Ar, CH4) reduce in number sooner than those for the smaller molecules (CO2, Ne, He), hence size-dependent migration between air pockets.
In his 1997 paper “Ice Core Data Show No Carbon Dioxide Increase” (http://www.21stcenturysciencetech.com/2006_articles/IceCoreSprg97.pdf) Jaworowski provides a more detailed diagrammatic representation of the vertical profile of an ice sheet and processes that act upon it. The gradual compaction of the air pockets, pores and channels is shown in the firn down to the transition to ice, saying “The firn density gradually increases with depth, and at 0.83 g/cm3, firn changes into solid ice” with no mention of any quantum change. Burrowing through solid ice by breaking H-bonds *, which you consider not to be size-dependent, could well take place within the (thin?) ice crusts that separate the different firn layers. These appear to start off as irregular coverings on the snow, with gaps/cracks and presumably also of varying thickness. I see the possibility of a degree of size-dependent migration of CO2 and smaller molecules there as well. Not
In your comment of March 24 at 10:42 am you say “Our aim should be I think to just list the uncertainties in a simple bullet point paragraph otherwise all that happens is that screeds of ineffectual writing is exchanged but for what?” I’m of the opinion that simply listing uncertainties achieves little. (BTW, in that comment you again mistakenly refer to 36 and 39nm instead of the correct 0.36 and 0.39nm. Is that why you believe that you “.. have produced a graphic .. that clearly shows firn pores are in the sub-millimetre dimension – not sub-nanometre .. ”?) In Section 5.1 CO2 in Glacier Ice: Changes in Original Gas Composition “ of their 1992 paper “Atmospheric CO2 and global warming – a critical review” (http://www.co2web.info/np-m-119.pdf) Jaworowski et al. identified the following uncertainties:
– the presence of clathrates,
– melt layers,
– microbubbles,
– adsorption of air components on the firn grain surfaces and enclosing the air during snowflake formation,
– interaction of CO2 with the ice itself,
– fracturing of the ice,
– chemical reactions between CO2 and impurities trapped in the ice,
– oxygen exchange between CO2 and water.
– dust content,
– acidity of the ice
– liquid water present in the ice even at extremely low temperatures.
My understanding is that many of these uncertainties remain 19 years later, yet paleo-climatologists like Richard Aller still insist that air “trapped” in ice sheets provides the “gold standard” for the reconstruction of past atmospheric composition (I’m of the opinion that it is more of a “fools gold” standard). This is why I believe that it is important to place a particular uncertainty in the spotlight an attempt to resolve it. My favourite is size-dependent fractionation of atmospheric gases.
In their paper “Do Glaciers Tell a True Atmospheric CO2 Story” (http://www.co2web.info/stoten92.pdf) Jawoprowski et al. provide an interesting graph in Fig. 3 which shows CO2 concentration v load pressure/depth in the ice. This indicates CO2 concentration falling from about 325ppm at 5bar (70m) towards an approximately constant level of 275ppm at 15bar * (180m) or lower. The researchers who produced these results from a Sipple ice core suggested that the cause was humans and the industrial revolution. Jaworowski et al. noted that when comparing figures from a Vostok core over a similar pressure/depth range there was a similar change in CO2 concentration, even though the ice ages were about 200-300 years Before Present for Sipple yet 4000-9000 BP for Vostok. Jaworowski et al. considered a more plausible explanation that the industrial revolution was differential diffusion and solubility, clathrate formation and micro-fracturing of the ice.
Their description of differential diffusion was “ .. lower molecular volume and .. viscosity of CO2 than N2, O2 and Ar. Differential diffusion occurs both in the ice sheet and in the ice cores .. ” – for “lower molecular volume” I read “kinetic diameter”.
You have been a great help so far so even though you seem reluctant to continue our exchanges on this issue if you can occasionally spare further time on them then I’d appreciate it. If not then thanks for engaging as you have because you have forced me to look even more closely at the papers that I have previously made reference to, as well as drawing my attention to some very useful new ones.
If anyone else out there is interested in jumping in on this issue then please do so.
* Just as an aside, while searching for information about CO2 clathrate formation in relation to the migration of CO2 through ice by breaking H-bonds I came across a 2003 paper “Clathrate formation and the fate of noble and biologically useful gases in Lake Vostok, Antarctica” by McKay et al. (http://web.me.com/daleandersen/Dale_Andersen/Science_articles_files/McKay%20et%20al.%202003.pdf). This shows in Table 1 the dissociation pressures for the different gases, with that for CO2 being 12.5bar, quite close to that 15bar at which the CO2 concentration in the air from ice pockets has levelled out to 275ppm. Is this just a co-incidence or was Jaworowski’s concern about the impact of clathration on those attempts to reconstruct past atmospheric CO2 concentrations more than just speculation, as claimed by supporters of the CACC doctrine?
Best regards, Pete Ridley
Pete, this is EXACTLY the quantum change, although in thermodynamics more often referred to as a phase change (change of state reserved for the solid-liquid-vapour changes).
This is where the the characteristics of the substance change radically. The pore sizes at the top of the firm will be discernible to the naked eye and at the bottom near the inclusion zone will need a light microscope because the smallest firm pores are maybe 0.1 millimeter dia.. Note that total pore close-off horizon is considered to occur below the inclusion zone so closure of pores to a sub-nanometer dimension will be closer to the bottom of the inclusion zone than the top, the closure being as much the result of the firn-ice transition as it is to do with pressure.
Pores in the solid ice molecular lattice are MUCH smaller and will not be discernible through a light microscope because the apertures are 0.00000036th of a millimeter in dia.
You seem to have no conception of scale. By comparison, cloud nuclei are in the region of 10nanometers (0.00001th of a millimeter) in dia but still not discernible with a light microscope.
By definition of firn vs solid ice, your hypothesis can only be valid in solid ice because any gas movement in firm will be as air – not individual constituent gases because there is no reason for fractionation (Mike Palin is correct in that).
I have produced, here it is again:-
3-D Snow and Ice Images by X-ray Microtomography
ESRF Newsletter No 35: June 2001
Results on firn and ice
Fig. 3: 2- and 3-dimensional images of ice around the firn-ice transition: porosities appear in black in the 2-D images. The episcopy technique reveals that the pores are located at crystal boundaries. 3-D reconstructions from the 2-D slices give access to the real shape of the porosities.
http://www.esrf.eu/info/science/newsletter/jun01/snow.html#fig3
The scale of the graphic for firm is clearly dimensioned in MILLIMETERS (3mm x 3mm square). The porosities are clearly in the sub-millimeter dimension. If you can’t see this you obviously have no conception of scale and are totally out of your depth. I can’t be bothered wasting my time repeating this concept ad nauseam if you continually fail to at least try to understand it. I have to say that my patience has run out and I now share Mike Palin’s frustration.
Hi Richard (C), thanks again for you assistance in trying to resolve this issue of the gradual compaction of a porous column of ice grains within an ice sheet to the state of being almost a block of solid ice. As you are aware (and frustrated by) I find your claim that there is a sudden quantum drop in the porous nature of the firn from having mm-size air gaps (channels) linking larger air pockets to a state where this porous nature suddenly vanishes and the only channels available for air to pass through reduce to sub-nm very hard to visualise.
In your comment of March 25 at 12:45 pm you refer to this as a phase change, which I also find hard to relate to since the little science that I have studied does not suggest that changing ice (the grains) to ice (the solid block) constitutes a phase change.
I understand you to then speculate that the smallest pores (and channels linking air pockets?) at the bottom of the firn “ .. are maybe 0.1 millimeter dia. .. ” and that there is a sudden “ .. closure of pores to a sub-nanometer dimension .. ”. That’s some quantum leap – to 1/1,000,000th the size (or have I once again demonstrated that I “ .. have no conception of scale .. ”.
I cannot understand why you keep thinking that the graphic presented in the ESRF Newsletter’s “3-D Snow and Ice Images by X-ray Microtomography” article (http://www.esrf.eu/info/science/newsletter/jun01/snow.html#fig3) is proof of the qhantum jump that you believe occurs. Even the experts Coléou1 and Barnolaat who presented the reconstructions say above that graphic that “ .. At 120 m, even if all the pores seem to be well isolated, some very small channels still exist and the gases can be fractionated when they diffuse through them .. ”. That is a 3mm cube they show and the size of channels that would allow particles the size of air molecules through are around 1/1,000,000th of that. I’m 74 so my eyesight isn’t as good as it was 50 years ago but even then I wouldn’t have been able to see channels that size on the graphic.
I speculate that you didn’t bother to look at the link I provided to “The firn zone: Transforming snow to ice” (http://www.iceandclimate.nbi.ku.dk/research/drill_analysing/cutting_and_analysing_ice_cores/analysing_gasses/firn_zone/). Had you done so you would have spotted just above the lovely photo of a slice through an ice sheet a link to “Cutting and analysing ice cores” (http://www.iceandclimate.nbi.ku.dk/research/drill_analysing/cutting_and_analysing_ice_cores/crystal_structure/). The first picture is of the crystal structure and beneath it says “..Ice consists of individual ice crystals, each with different physical properties. The typical size of the crystals in glacier ice is 1 – 5 mm, .. ”. Note how close that range is to the graphic that you depend upon, which shows a 3mm cube. Someojne like me wiuth no sense of dimension would jump to the conclusion that your graphic was showing a part of a single imperfect crystal of ice which has several small inclusions, probably air.
You go on to say of me “ .. you .. are totally out of your depth .. ” but I am not the only one, am I. Because I am not a scientist but a retired Chartered Electrical Engineer I make no pretence at having a deep understanding of the processes that occur in the ice (or for that matter any of the processes and drivers of global climates). That is why I have raised my concerns with specialists in the subject like Professor Hartmut Frank, Professor Zbinew Jaworowski, Professor Richard Alley, Professor Jeff Severinghaus, Professor Micheael Bender, etc. etc. etc. Not one of these “experts” has ever suggested that there is a quantum drop in the size of channels within firn as the firn ice is compressed to a more solid state which precludes preferential size-dependent migration of air molecules within the firn.
Taking that into consideration, perhaps you can understand why I am reluctent to take your word as gospel and why I am getting as impatient of your insistence that your opinion is correct and mine is wrong as you are vice versa. Of course you can easily remove this frustration for both of us. Simply provide a peer-reviewed paper that has been published in a recognised learned journal that shows the existence of this quantum drop in channel size when ice is crushed to ice.
When I exchange opinions with others I like to know a little about their background to find out if they have relevant expertise on which to base their opinions. I have tried to find details about your level of expertise in a relevant scientific or engineering subject but have drawn a blank. All that I know is that Richard Cumming is a blogger like myself, nothing more and nothing less. If I am wrong then perhaps you’d like to enlighten me.
Meanwhile I hope that we can continue having respectful exchanges of opinions and information without rancour. I made such a suggestion to Mike Palin on 21st March (http://hot-topic.co.nz/the-twilight-zone/comment-page-1/#comment-25161) but haven’t heard from him since 20th.
Best regards, Pete Ridley
Hi again Richard (C). You may be interested in taking a look at the 2000 paper “Snow crystal imaging using scanning electron microscopy: III. Glacier ice, snow and biota” by Rango et al. (http://itia.ntua.gr/hsj/45/hysj_45_03_0357.pdf). Fig. 10 on page 368 provides a SEM micrograph of old glacier ice with an elongated air pocket (bubble) of length about 1mm with bulbs at each end of about 0.2mm diameter. Fig. 11 on 369 magnifies this view about 15 times (I may have this wrong because of an inferior sense of dimension) to show an area within the pocket having what the authors say “ .. appears to be mineral particulates adhering to the ice .. ”. Of course, being totally out of my depth, they look to me like a line of pores of only a few microns diameter and numerous tiny speckles which could be more pores of a few nanometers or less diameter.
Figs. 13 & 14 provide excellent graphics of air pockets, the ice crystals that surround them and the channels that connect them.
Althoug Dr. Rango has moved on to other areas of research I have E-mailed him about your quantum drop in pore/channel diameter. If I get a response from Dr. Rango then I’ll pass it on here.
Best regards, Pete Ridley.
Posted at JoNova #17
http://joannenova.com.au/2011/03/david-evans-carbon-modeler-says-its-a-scam/#comments
Evidence for molecular size dependent gas fractionation in firn air derived from noble gases, oxygen, and nitrogen measurements
Huber et al 2005
http://icebubbles.ucsd.edu/Publications/Huber_closeoff_EPSL2006.pdf
The bottom of the firn is critical. This is the inclusion zone where firn transforms to solid ice.
Except they use an inappropriate diameter. They use collision diameter (molecules colliding with other molecules) when they should be using kinetic diameter (the aperture size that will let a molecule pass, CO2 collision dia 39nm, CO2 kinetic dia 33nm).
CO2 will pass 36nm if kinetic dia is used.
They have only considered a simple sieving mechanism. Others, notably Ideka-Fukusawa et al describe a hydrogen bond breaking lattice distorting mechanism where CO2 passes through the ice lattice.
http://www.nanonet.go.jp/english/mailmag/2005/054b.html
I don’t think so. I would be interested in any comments on this either here or at CCG [linked]
Hi Richard (C), thanks again for another plug on Joanna Nova’s blog of “Another Hockey Stick Illusion?”. The more discussion the better about my hypothesis regarding the preferential fractionation of CO2 out of air “trapped” in ice over decades, centuries and millennia and the oversight of the “experts” regarding the relevance of kinetic not collision diameter when diameters of the pores and channels approach molecular size.
Although I generally agree with how you have tried to summarise what I have been presenting here and elsewhere I suggest a couple of clarifications. First, you say that the fractionation through the small channels along the ice crystal boundaries is “ .. a simple sieving mechanism .. ” but it is not really a simple process within the ice sheet fabric due to chemical/physical complications. Even the “experts” in the subject like Professor Severinghaus, Dr. Huber, Professor Jaworowski, etc. find it less than “simple”. One of the possibilities that keeps coming to mind is the reduction in pore and channel diameter due to the adsorption of CO2 on the surface and the effect that this has on the migration of not only CO2 but other gas molecules.
A quick read of your comment may give the impression that it was Ideka-Fukusawa who said “This is an important confirmation for the integrity of polar ice cores as a climate archive of the ancient atmospheric composition of these gases.” It might help to make it clear that this was said by Huber et al. when concluding that “From our findings we believe that the effect of close-off fractionation is nonexistent or at least very small for isotope ratios and for large molecules, like Xe, Kr, N2, CO2, CH4, and N2O. This is an important confirmation for the integrity of polar ice cores as a climate archive of the ancient atmospheric composition of these gases”.
As I have pointed out repeatedly on this and the “It’s Not Warming … ” thread (https://www.climateconversation.org.nz/2011/03/its-not-warming-you-nitwit-its-cooling/#comment-45360), because it is kinetic and not collision diameter that applies in the bottom of the firn, they should have excluded CO2 from those atmospheric gases with kinetic diameters exceeding that magic 0.36nm.
BTW, if you’d like to see more excellent SEM views of polar ice structure (including those clathrate hydrate thingies that also affect the validity of the ice record) you can find some in the 2003 paper “SEM Studies of the Morphology and Chemistry of Polar Ice” by Barnes et al. (http://eis.bris.ac.uk/~glhmm/pdfs/BarnesMRT03.pdf). There is also a 2010 paper “Polar ice structure and the integrity of ice-core paleoclimate records” by Faria et al. (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBC-4XT2CSW-1&_user=10&_coverDate=01%2F31%2F2010&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=6e8a6cf329de2b66635d733b42ed5576&searchtype=a) but it has a $36/£30 price tag.
Am I correct in thinking that those CO2 clathrates are formed more readily than others because the smaller molecules can more readily force their way into the crystal lattice and replace H2O molecules. That is another of the concerns that Jaworowski talked about in his papers. Maybe one day I’ll find the time to get back to investigating that process and the adsorption issue. Why can’t you and I attract the interest of experts in this subject and benefit from their knowledge instead of having to struggle through our fog of ignorance? What a shame that Mike Palin withdrew from the exchanges on the Hot Topic blog (http://hot-topic.co.nz/the-twilight-zone/comment-page-1/#comment-25161). He claimed to have the necessary expertise.
I have just sent off an E-mail to Dr. Huber on the issue and invited him to join in the exchanges here. Let’s hope that he’s interested, although I was surprised to find that he appears to be a doctor of medicine, not physics or chemistry, so may not have the necessary expertise. If that’s the case perhaps he’ll be able to encourage his co-author Professor Severinghaus to join in – wouldn’t that be interesting.
Best regards, Pete Ridley
Hi Richar C, reference your comment of March 26 at 11:55 am and several previous ones, may I once again point out that ” .. CO2 collision dia 39nm, CO2 kinetic dia 33nm .. ” is two orders of magnitude too great. The commonly quoted sizes are 0.39nm and 0.33nm more often quoted in angstroms (Å).
Here’s a link to an excellent length convertor which includes nanometer (10 power -9 metres) to Angstrom (1 power -10)
http://www.convertworld.com/en/length/
Best regards, Pete Ridley
Meanwhile at NZs preeminent warmist site, this is how “the science” is peddled.
Apparently CO2 has a magnificent capacity to replenish the heating effect of LWIR back to what it was as SW, this then heats the earth’s surface even more than what incoming solar SW can. A truly amazing trace gas and all that from only 0.00029ppm atmospheric concentrations.
Should have been “from only 0.00039 of the atmosphere.” but you get the gist.
MattB at JoNova backed Palin’s statement. My response #204:-
——————————————————————————————————————————
MattB #197
No. The jumper prevents air circulation (is there a wind blowing?) so the heat that your body has already generated by metabolic means is unable to disperse but you have two heat sources – solar and metabolic (the earth’s internal heat source is hardly comparable to physical metabolism). So on a hot day, what makes you hot is the combination of factors: solar heat, body metabolism, no wind and unnecessary insulation.
Also, on a hot day there is no heat gradient through the jumper, its hot on both sides. If it was a cold day with no wind and direct sunlight you would be able to take off your jumper to receive direct sunlight illustrating that not only does insulation prevent heat going out, it prevents heat coming in in the form of solar radiation (think bikini skiing in the Alps). I live at the beach and see this demonstrated especially at this time of year (Autumn). If there is no wind, you can take your shirt off and be warm from the direct sunlight, meanwhile there are people bundled up in jackets looking cold, because they are not receiving the benefit of the heating effect of the solar SW radiation.
Even if there was a “greenhouse” barrier surrounding the earth preventing heat diffusion or convection the statement would still be rubbish. As soon as night-time comes and the solar heat source is removed, you are reliant on your bodies metabolism to keep you warm even with a jumper on. If you have no fuel to burn (food), your jumper wont help you much i.e. you will not be made hotter by your jumper.
Rubbish. The earths geothermal heat source aside, there is only one heat source, the sun. The greatest heating effect is from solar SW radiation. Once that radiation is re-radiated the heating effect is reduced due to the change in wavelength, SW to LW. The heating effect of the radiation is progressively spent every time it is reflected or re-emitted so a lessor form of radiation in terms of heating effect will never heat the earth’s surface to a temperature that is higher than the superior form does.
In summary: insulation is not a heat source. The more effective the insulation is as barrier to heat transfer and the less heat gradient there is, the more super-heating (heat accumulation) will occur over time (making you hot on a hot day with your jumper on) but no new energy is introduced by the insulation. There is not enough CO2 in the atmosphere to even come close to being that effective as an insulator, it is water vapour that does the bulk of work e.g. Sahara desert vs Singapore.
http://joannenova.com.au/2011/03/david-evans-carbon-modeler-says-its-a-scam/
A very useful article in this vein.
Understanding the Thermodynamic Atmosphere Effect
Joseph E. Postma (M.Sc. Astrophysics, Honours B.Sc. Astronomy)
Page 24 onwards being most useful.
Theory of the Greenhouse Effect vs. the Thermodynamic Atmosphere Effect
http://www.tech-know.eu/uploads/Understanding_the_Atmosphere_Effect.pdf
AGW vs physics basically
Hi Richard C(umming) that certainly is an interesting article that you link to (March 29 at 5:04 pm) but I wasn’t convinced of its authenticity. For example Iwouldn’t expect a scientist to say “The Greenhouse Theory is the proposition that the atmosphere warms the surface of the Earth to a temperature warmer than it would otherwise be without an atmosphere, via a process called “back-scattered infrared radiative transfer”. .. The word “radiative” in “radiative transfer” means “of or pertaining to light”; “transfer” is referring to transfer of energy. So radiative transfer means the transfer of energy by light”.
As I have said before, I’m a retired Chartered Electrical Engineer, not a scientist, but the small amount of science that I studied conflicts with what Postma says there. In my ignorance I understand that “radiative transfer means the transfer of any energy by radiation away from the source” not only by the limited range of E/M radiation within the band 4000 (violet) to about 7700 (red) angstroms.
Related to this is Postma’s claim that “ .. A blackbody is simply exactly what it sounds like: an object which is completely black. The reason why it is black is because it absorbs 100% of all the light that strikes it, and doesn’t reflect any of it back. Therefore it appears black! .. ”. Once again my understanding differs because to me a black body is a QUOTE: .. full radiator (a hypothetical object capable of absorbing all the electromagnetic radiation falling on it) “a black body maintained at a constant temperature is a full radiator at that temperature because the radiation reaching and leaving it must be in equilibrium” UNQUOTE (http://wordnetweb.princeton.edu/perl/webwn?s=black%20body). Note that reference to ALL e/m radiation, not just light.
When I reached the point where Postma said “ .. So strictly speaking, although the blackbody absorbs all the light that strikes it, it wouldn’t actually appear perfectly black at all wavelengths because the thermal energy it re-emits is also a form of light. But it appears black because this re-emitted light is of a much lower energy than the light being absorbed. For example if the object absorbs visible light, then it will re-emit infrared light which we can‟t see, and therefore it still appears black .. ” I decided to stick with more dependable analyses such as provided by retired award-winning Canadian science teacher Roger Taguchi on Judith Curry’s “Physics of the atmospheric greenhouse(?) effect” thread (http://judithcurry.com/2010/11/30/physics-of-the-atmospheric-greenhouse-effect/) and I once again recommend that you read them (my comment of March 30th at 3:54 am on http://joannenova.com.au/2011/03/david-evans-carbon-modeler-says-its-a-scam/comment-page-5/#comment-249733). As I said then, in particularly see Roger’s comments of 7th, 9th, and 22nd Feb.
At that point I decided not to waste my time reading further to skipped to the end and realised why Postma’s article struck me as less than reliable. He says “I would like to thank the organization of scientists known as the “Slayers” for their support, their insight, and most importantly, their inspiration. Your work and your intellectual standards are the highest and closest representation of the ideals of our Natural Philosophy, extending across the thousands of years of history in our human development. A special thanks goes out to Hans Schreuder, for editing this manuscript, for his moral support, and for his friendship”.
I was closely involved with “The Slayers” during December 2010 and Jan/Feb 2011 at the invitation of their leader John O’Sullivan and at one time he expressed interest in including a chapter on my hypothesis about the dubious ice-core record in their next book. That same team put out an appeal for charitable donations to help them set up their company Principia Scientific International which you can read about on the GoFundMe site (http://funds.gofundme.com/1v39s). I leave it to you to guess where that first £350 came from. Don’t forget to read the comments on that page. There are plenty more if you want them.
In my humble opinion there are more dependable sources of information than Postma’s article, but of course I may have this all wrong because once again as you said before of me (March 25, 2011 at 12:45 pm) “ .. If you can’t see this you obviously have no conception of scale and are totally out of your depth. .. ”. Perhaps you will have enough patience to get round to explaining for me where I have misled myself. After all, I’m always happy to learn something new, unlike some.
Best regards, Pete Ridley
I could have referenced G&T 2009 but the Postma article is more readable. G&T are far more explicit in their condemnation of the unphysical basis of AGW:-
——————————————————————————————————————————
Falsi fication Of The Atmospheric CO2 Greenhouse Eff ects Within The Frame Of Physics
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
5 Physicist’s Summary [relevant points]
A thorough discussion of the planetary heat transfer problem in the framework of theoretical
physics and engineering thermodynamics leads to the following results:
1. There are no common physical laws between the warming phenomenon in glass houses
and the fi ctitious atmospheric greenhouse eff ect, which explains the relevant physical
phenomena. The terms “greenhouse eff ect” and “greenhouse gases” are deliberate misnomers.
6. Re-emission is not reflection and can in no way heat up the ground-level air against the actual heat flow without mechanical work.
7. The temperature rises in the climate model computations are made plausible by a perpetuum mobile of the second kind. This is possible by setting the thermal conductivity
in the atmospheric models to zero, an unphysical assumption. It would be no longer
a perpetuum mobile of the second kind, if the \average” fi ctitious radiation balance,
which has no physical justi fication anyway, was given up.
8. After Schack 1972 water vapor is responsible for most of the absorption of the infrared
radiation in the Earth’s atmosphere. The wavelength of the part of radiation, which is
absorbed by carbon dioxide is only a small part of the full infrared spectrum and does
not change considerably by raising its partial pressure.
9. Infrared absorption does not imply “backwarming”. Rather it may lead to a drop of
the temperature of the illuminated surface.
—————————————————————————————————————————–
Basically, LWIR does not equate to solar SW in heating effect and is degraded by scattering, re-emission, reflection and wavelength change to such an extent that is does not heat oceans, lakes or rivers and does not heat the earth beyond what solar SW has already heated it. Add to that the limited part of the infrared spectrum that CO2 absorbs and the case for catastrophic global warming is lost.
It doesn’t matter how “dependable” a paper or article is in detail because in the real world the phenomena of accumulating heat is not being observed i.e. the AGW hypothesis is being disproved by the scientific method but conventional physics provides the most plausible explanations for what we do observe even though the interpretations may differ from paper to paper to some degree. To those still wedded to AGW, those explanations from conventional physics are unpalatable and to be villified at every available opportunity so presenting G&T will just garner a dismissive reaction from the likes of MattB.
The main point is that the most credible, comprehensive and persuasive arguments against AGW are coming from first, the empirical measurements and second, the thermodynamic explanations coming from physicists (or astrophysicists) that are in sync with what is being observed. G&T and Postma are not the only voices from physics that present similar arguments but compare the relative compatibility of their explanations to each other and to the observed condition to that of climate scientists notably Kevin Trenberth who are now at odds with the observed condition because they cannot accept that their AGW hypothesis is being falsified by the metrics that they have assumed would prove it.
A further delusion for AGW is that erroneous and over simplistic physical mechanisms have been transferred to the models with the predictable result that the simulations do not mimic real world conditions now that the apparent 1977-1997 CO2/temp correlation has run its course. Bob Tisdale is highlighting how the GISS model is not mimicing ocean heat partly because of the assumption that CO2 plays a greater role than it does and partly because natural phenomena are ignored.
http://bobtisdale.blogspot.com/2009/10/why-are-ohc-observations-0-700m.html
http://www.c3headlines.com/2011/03/climate-models-fail-stupendously-at-predicting-ocean-warming-new-data-shows.html
I think that those who reject the scientific argument that increasing the global mean atmospheric CO2 concentration causes an (insignificant) increase in mean global temperature would benefit from reading the analyses carried out by Roger Taguchi (my comment of March 30th at 10:12 am).
I Googled – “Joseph E. Postma” biography – and the first site up was Climate Realists (http://climaterealists.com/index.php?id=7457&linkbox=true&position=2) with some interesting exchanges between Postma and others, particularly Stephen Wilde. The comment that impressed me most was “Posted by Bomber_the_Cat on Mar 29th @ 7:23 AM EDT: Joseph, this sort of nonsense is not very helpful to the sceptic cause. Your article, apart from being unsound, is best described as very rambling. Sorry, I tried to persist but gave up about page 28,; there is only so much nonsense you can absorb in one day”.
What I found even more interesting were the bios of who are behind that blog, including Hans Schreuder (proposed PSI Executive Board Member and CFO) and Piers Corbyn (closely involved with PSI). Who should be on the Home–page but Tim Ball (“Slayer” and proposed PSI Chairman). Then, offering an article about him and “ .. the second of two libel lawsuits from North Vancouver law firm of Roger D. McConchie on Friday (March 25, 2011). Global warming doomsaying professor Michael Mann files the latest writ .. ” (http://climaterealists.com/index.php?id=7445&linkbox=true&position=1), was no less than John O’Sullivan, the Slayers “project leader” and proposed CEO of Principia Scientific International (PSI).
Talking about “hockey team” captain Michael Mann, “the Slayers” and PSI reminds me of exchanges I have been having recently on the Bishop’s Hill blog run by Andrew Montford, author of that excellent CACC exposé “The Hocket Stick Illusion”. During those exchanges I made reference to “The Slayers” (Mar 29, 2011 at 1:04 PM and Mar 30th at 2:56 PM) which you might like to have a look at. I have also suggested to Andrew that he might be interested in looking at “Another Hockey Stick Illusion?” created from air “trapped” in ice for millennia (http://bishophill.squarespace.com/blog/2011/3/28/light-blogging.html#comments Mar 28th at 10:07 PM). Andrew is due back today so I hope that he takes an interest in this.
Dr. Jeffrey Glassman, who runs the Rocket Scientist’s Journal blog (http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html), has made a couple of helpful comments on this issue on Judith Curry’s “Agreeing” thread (http://judithcurry.com/2011/02/26/agreeing/#comment-57880) which may be of interest to you.
Best regards, Pete Ridley
Pete, there is a large repository of peer-reviewed science already at this blog, you may wish to add what you think is useful. Either use the “Open Threads” button at the top of the blog page or use this INDEX:-
https://www.climateconversation.org.nz/open-threads/climate/disproving-agw/#comment-26342
Topics in that index are as follows but you will find a different index using the Open Threads button:-
Disproving AGW
Controversy and scandal
Climate
Economics
Politics
Energy and fuel
ETS and carbon taxes
CO2
Climate science
Atmosphere
Water Vapour
Temperature records
Ocean and Heat
Solar and Cosmic
NIPCC
IPCC science
IPCC organisation
IPCC politics
UN
News
New Zealand
Australia
UK
USA
Europe
Asia
Pacific
South America
Africa
Sea levels
Polar regions, glaciers and ice
Global warming
Ocean acidification
If you subscribe to the blog with Google reader you will keep up with comments to all posts and additions to Open Threads topics.
One of my favourites under “Climate Science”
A NULL HYPOTHESIS FOR CO2
Roy Clark, Ph.D.
ABSTRACT
Energy transfer at the Earth’s surface is examined from first principles. The effects on surface temperature of small changes in the solar constant caused by the sunspot cycle and small increases in downward long wave infrared (LWIR) flux due to a 100 ppm increase in atmospheric CO2 concentration are considered in detail. The changes in the solar constant are sufficient to change ocean temperatures and alter the Earth’s climate. The surface temperature changes produced by an increase in downward LWIR flux are too small to be measured and cannot cause climate change. The assumptions underlying the use of radiative forcing in climate models are shown to be invalid. A null hypothesis for CO2 is proposed that it is impossible to show that changes in CO2 concentration have caused any climate change, at least since the current composition of the atmosphere was set by ocean photosynthesis about one billion years ago.
https://www.climateconversation.org.nz/open-threads/climate/climate-science/#comment-26629
Another possibility is “Open threads as promised” where you can explore something topical that is not being covered elsewhere. There’s some rubbish at the top from when it was first introduced but further down I’ve made good use of it. Nothing to stop you commandeering this thread of course to continue documenting your ice core investigation and anything else (the blog master Richard Treadgold may issue directions so keep an eye out for that).
https://www.climateconversation.org.nz/2010/10/open-threads-as-promised/
I’ve used it to explore radiative transfer models and climate models in general (there’s more of that in “Climate” and “Climate Science”. I’ve also used it for pollution as related to the climate change issue.
I’m sure you will find access to as much useful climate change related science at this blog as anywhere on the internet.
I’m off to the kiwifruit harvest for the next few months so “see ya all” (11/7 first few weeks from tomorrow)
Hi folks, sorry that I’ve neglected you all since Richard Cumming headed “ .. off to the kiwifruit harvest .. ”. A lot has been happening in w.r.t. the “fallen snow” issue in the last 6 weeks. On 13th April, after some further research into the structure of the firn in an ice sheet, I took my question to the Science Forum of “The Naked Scientists … a media-savvy group of physicians and researchers from Cambridge University .. ” (http://www.thenakedscientists.com/HTML/about-us/)”. The discussion is available (for now, until their adsmin team decide to remove all traces of me) under the thread title “Another Hockey Stick Illusion?” (http://www.thenakedscientists.com/forum/index.php?topic=38675). I summarised my question as “why do paleo-climatologists use collision diameter in preference to kinetic diameter when considering the migration of air molecules through firn and ice?” and provided additional information to supplement the question.
They were unable to answer my question so on 20th April I contacted Professor Eric Wolff of the British Antarctic Survey. Professor Wolff responded with several detailed and helpful comments, but I remained unconvinced. In his final submission on 2nd May, after having discussed my question with Professors Richard Alley and Jeff Severinghaus, Professor Wolff responded with “.. the specific answer is that they use collision diameter because this is what allows them to rationalise the data that they observe”. That fits with the responses I had previously been given by other specialists last year but I am still not persuaded by that argument on the basis that the use of collision diameter rather than kinetic diameter only fits their interpretation of the data, which may well be flawed.
In a nut shell I say that it can be flawed because the deep firn in an ice sheet is a nanoporous medium and expert practitioners in the movement of individual gas molecules in nanoporous media, such as zeolites, use kinetic diameter in their design analyses and in their models. Professor Zbiniew Jaworowski, who has repeatedly challenged the validity of the ice core record snce 1992, said in an E-mail last June that “I am also not versatile in diffusion, and writing my paper in 1994 I was advised and enlightened by a geologist from the Norwegian oil industry, who was specializing in diffusion, a subject of great importance for oil industry. This is a highly specialized field of science. My impression is that it is a terra incognita for glaciologists”.
That comment by Jaworowski needs to be taken into consideration alongside Professor Wolff’s statement that “I think that none of us has a definite molecular level understanding of the physical process occurring at close-off, and it would be great if someone can do the experiments in the lab to understand that better. But it won’t alter the empirical facts”.
I can’t argue with that but if this process was properly understood it could change the way that those empirical facts are interpreted. I have just contacted an expert in the modelling of the porous structure of zeolites, Professor Christodoulos Floudas, Princeton University. NJ, USA. Hopefully he can make some time to add his expertise to the discussion.
Anyone interested in finding out more about the discussion with Professor Wolff should read the comments on the “Another Hockey Stick Illusion?” thread. There is also another interesting set of related exchanges on another thread “What does Iain Stewart’s “CO2 experiment” Demonstrate” http://www.thenakedscientists.com/forum/index.php?topic=38723 (both of which have now been locked by The Naked Scientists admin team and my access rights removed) and on the Global Warming (or is it Global Cooling?) blog:
– “Hasn’t anyone ever heard of the Medieval Warm Period?” thread
http://rogerfromnewzealand.wordpress.com/2010/01/02/globalwarmingorisitcooling/ and
– “SUZUKI ELDERS:-We’re doomed” thread http://globalwarmingsupporter.wordpress.com/2011/05/08/suzuki-elders-we%E2%80%99re-doomed/.
Please drop in for a chat.
Best regards, Pete Ridley