Does climate sensitivity depend on the cause of the change?
Can a response to a forcing wait and then bounce up after a period of inertness?
Does the existence of an 11-year time-scale prove the existence of solar forcing?
Why does the amplitude of the secular response drop when a long-term trend is added?
These are perhaps some of the questions that we might hope to see discussed in the sequel to the sequel on solar forcing by Scafetta & West (S&W), a few of which have been discussed before here and here. (I still think those earlier studies were seriously flawed and showed a lack of scientific understanding, by the way).
This time S&W present a set of new arguments and a new set of results which are scattered all over the place. The impression from reading their paper is that the upper range (they call it ‘upper limit’) is probably more representative than the lower estimates for the solar contribution to the global mean temperature.
I think that many of their arguments, on which this impression is built, are shortsighted. For instance, they claim that certain climate reconstructions must be wrong because they give ‘unphysical’ answers. But there is another explanation too that they did not contemplate: their idealistic (one may also argue unphysical) model may also be wrong! Thus, they fail to exclude other explanations.
S&W attach the ACRIM Total Solar Irradiance (TSI) product (not the PMOD product, probably because that does not show any trend) to a TSI reconstruction (Lean 2000 TSI [see Lean, 2004], or Wang et al., 2005) in such a way that the average reconstructed TSI value over 1980-1991 corresponds with the ACRIM mean for the same period – never mind the discrepancies in trend and that such cavalier stitching of data series is one of the deadly sins in climatology (hint: the series is inhomogeneous).
One new aspect of this S&W study is the focus on ‘feedbacks’. They assume the TSI reconstruction is a proxy for the total solar influence and that CO2 is part of a solar ‘feedback’ (isotope ratios suggest the CO2 comes from deep underground reservoirs, but it’s not clear how the sun manages to dig up this carbon from deep below Earth’s surface).
S&W maintain that the climate response is greater for longer time scales (which is reasonable) as illustrated in their figure 4 (reproduced below), and assisted by the simple model illustrated in this figure, they argue that the present warming is a delayed response to past solar changes (presumably before the 1950s). But it is unclear why the temperature then flattened out and even dropped a little between 1940-1970 at the time when it really should have increased fastest. One could argue that something else also happened then, but for an unknown reason, this forcing then seemed to have a shorter relaxation time. Why such an interference would give a quicker response than a solar signal is unexplained (the response to volcanoes is fairly prompt, however).
The study by S&W has some suspicious results. When their simple ‘phenomenological thermodynamical model’ (PTM) is forced by a signal with shorter time scales (high-frequency response representing the ~11-year solar cycle), it produces weaker response than if the forcing has longer time scales (or lower frequency) – as expected. But if you add a long-term trend to the former, the amplitude of the high-frequency response diminishes further (their Figure 4, reproduced above): The amplitude of the higher frequency response in their upper panel (4mm measured in the print) had diminished by ~50% in the lower panel (2mm). This is probably because the relaxation time response has been increased between the two panels and is greater than 10 in the lower panel. The presence of a trend should not affect the amplitude of the higher frequency in such a simple linear system (see my reproduction above).
Their figure 5 (below) does not correspond with the discussion in their paper (see scanned part of the text). Again, their analysis is sloppy in the estimate of change, underestimating the observed temperature change (T(obs) in Fig 5a, the total warming is stated to be ~0.8K since 1900, but the figure suggests it is greater than 0.8K) and exaggerating the solar contribution T(sol). This way, the fraction T(sol)/T(obs) gives the impression of a more sensitive response to changes in the Sun. They then proceed to use the lower T(obs) estimate for Mann & Jones (2003) for the total temperature change (claiming 0.8K, although this is too low), but taking a solar contribution estimated from the Moberg et al. (2005) temperature with more pronounced variations (the right estimated warming should exceed 1.0K – not 0.8K as they claim). Hence the fraction of solar signal to total change T(sol)/T(obs) is spuriously inflated.
But what about GHGs if the sensitivity is so high and the relaxation time is so long? We know from laws of physics and lab measurements that the CO2 levels have been increasing and that CO2 absorb infra red radiation. In fact, the Mauna Loa observations done by infra-red gas analysers measure the absorbing properties of air samples – a pure GHG effect on a microscopic scale without feedback effects. The high climate sensitivity and long time delay suggested by S&W would be scary – imagine the GHG warming that is not yet materialised and would be in the pipeline! (Lindzen who doesn’t believe in the lagged response would indeed be surprised if this was the case!).
S&W propose two mechanisms which may amplify the response to solar variations: (i) GCR (here, here, here) or (ii) UV-radiation.
But S&W ignore the issue about the lack of trend in the GCR (Lockwood & Frohlich, 2007; Benestad, 2005), the fact that trends in the diurnal temperature suggest otherwise (IPCC, 2001, 2007), and that there is not a clear trend in the cloud cover. Thus, explanation (i) is not convincing.
The problem with the UV-explanation (ii) is that the stratosphere has been cooling – some of which is due to the ozone depletion. How could they have ignored that?
Finally, the paper oozes of vague but subjective and cherry-picked statements forming the impression that the climate and solar reconstructions of Mann & Jones (2003) and Lean (2000) (why not use more recent reconstructions, by the way?) respectively are less accurate than others. Apparently because these do not give the desired results.
The paper also offers some incorrect references (Kristjansson et al, 2004, do not support the notion that GCR affect the climate). Furthermore, their paper contains little physics, but is little more than a curve-fitting exercise with no cross-validation.
Thus, S&W make a number of unjustified assumptions and sweeping statements which turns it into a mere speculation. In a way, the conclusions are already given when S&W assume that the sun is the predominant cause from the outset. S&W presumes a desired conclusion when arguing that if the TSI variations are small but the temperature variations are pronounced, then this suggests greater climate sensitivity and vice versa. No surprise, their conclusion is that the sensitivity to solar changes is high. Any other conclusion would then be surprising, wouldn’t it?
If they were my students, I’d have flunked their paper.
PS to Barton
On the way to get coffee — bring in Thermo’s First and you can drop Kepler’s Second.
Again, at the risk of going off-topic (the more relevant threads have been closed to comments, or are showing waning interest), the following might be of interest to RC visitors, esp. those debating policy and technological solutions:
A Convenient Guide to Climate Change Policy and Technology
published by the Climate Change Policy Partnership at the Duke University Nicholas School of the Environment and Earth Sciences and Nicholas Institute for Environmental Policy Solutions
Center on Global Change
“Scientific consensus, growing public awareness and political change may soon drive the United States to a mandatory climate policy. Fossil fuel-generated electricity accounts for one-third of carbon dioxide emissions in the United States; electric utility companies can therefore provide leadership in technology and policy development through careful investment decisions for future generation capacity. This 420-page guide from the Nicholas Institute and Duke’s Center on Global Change examines technology options for reducing utility-generated greenhouse gas emissions and reviews policies to achieve reductions.”
http://www.nicholas.duke.edu/ccpp/convenientguide/
Check out the NOAA SST historical database. The artic ocean north of Norway/Finland/Western Russia almost always shows strong positive SST anomalies, going back for at least five years that I checked. I think the SST database only goes back 20 to 25 years, so either was an early history of much colder water at those locations or something is wrong in the reporting. Maybe the area had historically been covered with ice and the SST calculation has trouble dealing with that.
In addition to gale force winds, there has also been a strong flow of warm Pacific air via the Bering Sea. Jim Andrews at Accuweather has written a piece:
http://www.accuweather.com/news-blogs.asp?partner=accuweather&blog=andrews
Hank Roberts (#195) wrote:
How about Peter’s Projection? Project horizontally onto a cylinder and an area on the map will be proportional to the area on the globe. In any case, the sea ice area is still climbing according to Cryosphere Today, but the anomaly is has dipped back down again – although it looks like it’s begun to climb back on the monthly.
Thanks for the several pointers Pekka, very helpful to have the polar projection.
Jim Andrews comments that he doesnt’ have access to info from the area, but the US Navy certainly does.
This is from several years ago, a Google grab’n’run, I’m sure there’s more recent info. Anyone know where to find it?
4/23/2003
http://www.onr.navy.mil/media/article.asp?ID=58
Office of Naval Research Sends Scientists to Arctic Ice Camp
In late March [2003], the U.S. Navy established a camp on a severe and unforgivingly cold stretch of ice about 150 miles north of Deadhorse, Alaska…..
… “Rapid change in Arctic temperature is like the canary in the coal mine,” explains Dennis Conlon, Arctic scientist at ONR. “Arctic ice cover affects Earth’s temperature. The less ice there is to reflect sunlight back into space, the warmer we get. This ice camp gives researchers the chance to gather data and to help the Navy better understand the Arctic operational environment.”
Martin Vermeer (#188) wrote:
Spencer is studying the Madden-Julian Oscillation as a means of determining the effects of higher temperatures upon cloud formation over the ocean. But there is only one problem: as this is an oscillation, what you are dealing with is periodic behavior which by its very nature dynamic, not static, yet you are trying to draw conclusions about what will essentially be static from it – what happens when the higher sea surface temperature forces the system to equilibrium – and the clouds that are associated with that equilibrium.
To see the problem with this, imagine trying to calculate the relationship between the climate’s sensitivity to solar insolation – on the basis of the difference in temperature between day and night. Obviously you can’t draw a conclusion regarding the temperature that the earth would be if days were as dark as nights simply on the basis of how cold the nights are – because nights haven’t had the chance to achieve equilibrium.
Anyway, a slightly wordier way of what Gavin gave some time ago — but essentially the same response as what you gave.
RE: # 185
Wayne, you mentioned in # 197:
[I observed several Cyclones hitting towards the Pole over the last 12 days, mainly from the Pacific, some from the Atlantic ]
If intense wave action broke, scattered and shoved aside massive expanse of thin, new ice an equally massive surface of open water with warmer water from below upwelling and releasing heat suddenly that would account for the extraordinary spike in temperature.
The rapid formation of new ice means it is likely very thin and the link Pekka provides at # 198
[An Arctic sea ice area time series is found on page http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg As the winds come and go, there are typically several dips in the ice area each winter. The long term trend is clearly diminishing.]
indicates this rapid freezing could not have added much thickness to the new ice surface.
Thus, heavy wave action broke up ice and allowed warm upwelling seawater to the surface to give a huge jolt of heat to the atmosphere in a very short period of time.
RE # 205
Timothy, you said:
[the sea ice area is still climbing according to Cryosphere Today, but the anomaly is has dipped back down again – although it looks like it’s begun to climb back on the monthly.]
Look at the link Pekka provided at:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg
and note the exceedingly rapid increase in ice area and you will not find a similar event elsewhere on that graph.
Rapid freeze over a few week period means very thin ice prone to rapid destruction by intense wave and wind action.
RE # 185
Wayne:
Jim Andrews at Accuweather provides the gridded data (surface temperature) for 11/29 and 12/2.
Look at the temperature changes from Thursday to Sunday and you will see the graphic of the great red temperature explosion.
Arctic Warming
Thursday, November 29, 2007 and Sunday, December 2, 2007
http://www.accuweather.com/news-blogs.asp?partner=accuweather&blog=andrews
William Astley (#182) wrote:
Bond? You are doing better. He gets cited by those who discount the greenhouse effect, but he himself of course recognized it. How could he not? Its grounded in solid physics. And carbon cycle feedback would have amplified such solar oscillations. Likewise, I doubt that any competent climatologist would fail to recognize that solar was the dominant forcing throughout all of the Holocene — prior to the 1800s.
However, the oscillations that he argued for were considerably weaker than the Dansgaard-Oescher oscillations — although presumably a continuation of them into the Holocene. But I personally don’t know how well his theory has held up. And in any case, the oscillations would have still been local — as the southern hemisphere would have dipped whenever the northern hemisphere rose.
*
It would appear that best estimates, the Holocene maximum was set roughly 7500 — prior to being shattered in the late twentieth century.
Please see:
Holocene climatic optimum
http://en.wikipedia.org/wiki/Holocene_climatic_optimum?uselang=en
If I remember correctly the data would seem to suggest that we are already above any temperature that has been reached in the past half-million years. And we are still climbing.
PS
Sources for the data off which the graph is based are given with the most recent being 2004.
..and so (if my simple appreciation of weather-drivers holds) all that warming air will now be rising in cells and pulling more air in from someplace else. And that new air will be warmer still. A nice positive feed-back. Flip or tip?!?!
Ref 209 John McCormick writes “Rapid freeze over a few week period means very thin ice prone to rapid destruction by intense wave and wind action.” I tried the Pekka piece (198) for the reference, but could not find it. Could you give me a reference where this is shown to be true?
..and of course wind velocity will be increasing as the temperature differential increase – which will increase the upwelling of the arctic ocean – which will – … oh darn!
John L. McCormick () wrote:
I believe the anomaly minima was reached around October 1, and that would have been when the rise you are looking at begun. There has been a smaller dip just recently, but a rise has begun again. But yes, the ice is quite thin at this point.
I am somewhat higher than 50/50 on whether we will set a new minima this coming year. Dramatic minima aren’t usually broken the following year — but there is the positive feedback, and it would appear to be fairly strong. However, that opinion is probably not worth much more than a plug dollar — even with inflation.
Did the article you would have ‘flunked’ (had they been written by students) pass peer review? If you are correct, does this not imply that the quality of the peer review process for the climate sciences is appalling bad? If so, how can other articles be trusted if their primary defence is ‘peer review’ as is regularly asserted by environmentalists and the media? As I have an interest, but no expert knowledge in the climate sciences, how am I to therefore evaluate of the quality of any of the published papers?
[Response: “Peer Review: A Necessary but not Sufficient Condition”. – mike]
re: Jim C. @ 213
Perhaps I am missing something, and I am open to correction, but which part of John M.’s statement strikes you as being a non-obvious or requiring study? To put it another way, can you imagine any plausible scenario in which the recently, rapidly reformed ice isn’t thin? Or any reason why thinner ice wouldn’t be more easily broken up than thicker ice?
Since Palle has come up in this thread a few times, brief excerpts from a couple of articles detailing some of the problems with his approach, one being from Real Climate itself….
First, it appears that he wasn’t taking into account the greenhouse effect that results from clouds in his calculation of the effects of reduced cloud-cover…
Second, it appears that he was greatly overestimating the presumed changes in cloud-cover…
Third, the trend reversed itself in recent years. Fourth, qualitatively the measurements which he describes would seem consistent with solar brightening as the result of declining aerosols. And if so, so much for any connection to cosmic rays.
Have I missed anything?
Ref 217. I live in Canada. I have spent time in winter in Fort Churchill. So far as I am aware, ice thickens according to Newton’s Law of Cooling. If the air temperature is cold enough, ice thickens very fast indeed. I have seen no mention of what the temperature was where the ice froze, My guess is if the surface was covered fast, the air temperature was very cold, and the ice would thicken very fast. Here in Ottawa with temperatures only down to -30 C, the ground will freeze to 7 feet in two weeks, providing there is no snow cover.
Re #207: Just to add that the reduced sensitivity that Spencer says is implied by his results runs into insurmountable difficulties when paleoclimate is considered. The deglaciations, e.g., involve some pretty sharp temperature increases that are hard to imagine if tropical warming is damped like that.
My impression is that the Spencer paper (and let’s not forget the co-authors, including Christy) is considered to be pretty much in the “not even wrong” category, and so is not deserving of a formal reply.
If someone does write a reply, though, I have a suggested title for them:
“Far from the Madden crowd: Spencer julienned”
For Will Nitschke #216 and the other nonscientists here, peer review is a minimum standard. It is a determination by a few experts in the field that an article is of sufficient interest to the larger community that it merits publication and consideration by that larger community. The community of experts then decides on how correct and important the work is–as measured by, for example, the number of times the work is cited in other peer-reviewed articles. Suffice to say, I don’t think Rasmus (or most other climate scientists) will be citing S&W except as a strategy that doesn’t work.
Jim Cripwell (#213) wrote:
Kevin Stanley (#217) asked:
… in response Jim Cripwell (#219) wrote:
Just out of curiosity, how quickly does land flow in Ottawa, and how big are the waves?
RE # 213
Jim, compare the Nov 27 with the Dec 4 and I believe you will notice a decreased ice cover on Dec. 4. It was during the Nov 27-Dec 4 several cyclones visited the Western Arctic according to Wayne Davidson. Very thin ice and strong wind and wave action likely caused the decrease by Dec. 4.
Dec. 4: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20071204.jpg
Nov. 27 http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20071127.jpg
Re :185 http://www.cdc.noaa.gov/cgi-bin/HistData/fnl.pl?date1=&date2=&days=1&va
r
Arctic is very warm now. Link:http://www.cdc.noaa.gov/cgi-bin/HistData/fnl.pl?date1=&date2=&days=1&var=Air+Temperature&level=2000&type=1&proj=Northern+Hemisphere&custproj=Cylindrical+Equidistant&xlat1=&xlat2=&xlon1=&xlon2=&labelc=Color&labels=Shaded&cint=&lowr=&highr=&scale=200&Submit=Create+Plot
#210 John, It went warmer than the grid as on the link, not only on the surface but the tropopause reached 11 to 12 kilometers! Again I stress this is a new Arctic disorder of weather, especially completely different temperature wise, your assessment basically means shallow ice thickness and open sea coverage is intertwined with atmospheric temperatures in darkness especially as Nigel wrote in 214, if winds are involved. Current sat pics show numerous almost countless leads where the Arctic Ocean open water was in September. For those of us experienced in looking at Polar sat pics of the 80’s and 90’s, this open water amongst thinner ice is a new landscape near the pole of November and December. Given calm wind conditions, it got cold, almost normally cold, after all darkness makes the Arctic what it is. The Accuweather meteorologist called this temperature boost a “freak” event, true enough, it use to be a freak rare event, but now things are changing to the point where it’s becoming very common.
How then did it come to this? On topic, the sun is nowhere to be found, we are at a solar minima, -5 at the Pole in December. Surely there is more energy from atmospheric chemistry, in its properties of heat retention with its various radiative mechanisms, than a sun quiescent, hidden in the Earth’s shade.
I am somewhat higher than 50/50 on whether we will set a new minima this coming year.
Timothy how about a wager on that? $100 (or Euros) says it 2008 minima > 2007
Sorry I am not implying that peer review is without limitations. But I am wondering (as a non-scientist but someone who does work in a technical field) that if the published paper is of such poor quality that it would get an ‘F’ if done by a student, then:
1. Is climate sciences in a state of shambles?
2. Is the reviewer using hyperbole in expressing this opinion?
Would one get a paper published in a medical journal if the author of the paper would not even get a pass mark on it as an undergraduate?
Are other established scientific fields so contentious over particular issues? I am finding my reading of the ‘pro’ and ‘anti’ CO2 hypothesis literature disturbingly ‘filtered’ by all sides of the debate.
[Response: No, climate science is not in a shambles. Most papers that pass peer review are correct; many of them are uninteresting and never get read, but the filter works reasonably well. Some papers are (mostly) technically correct in their execution but make dubious assumptions and draw unfounded conclusions. The paper by S&W under discussion here is in that category. No one paper that passes peer review can be taken on that basis as absolute truth. You have to look at the ensemble of what is published, and on the follow-up in other papers. There is no replacement for actual understanding of the contents, and in the absence of time or background to
do that, one must settle on reliable authorities (like IPCC) to do the vetting for you. Still, I think many of the fundamental issues are readily accessible to the lay reader, even if making sense of the vast literature can be overwhelming. –raypierre]
RE 221 Ray,
when you guided this discussion from disorder back to the main topic of the title, the Sun, I see you have yet no comments on the study
Usoskin, Ilya G., and Gennady A. Kovaltsov, 2007. Cosmic rays and climate of the Earth: possible connection. Comptes Rendus Geoscience, accepted October 30, 2007, in press, online http://cc.oulu.fi/~usoskin/personal/CRAS2A_2712.pdf
I copy what Ilya thinks an interesting relation:
“Numerous studies (see reviews [16,81,91]) confirm a
relation between solar/CR activity and different indices
of climate behaviour (e.g., d18O or drift ice debris [8]) during the Holocene.
For example, there is an apparent agreement between
the grand minima of reduced solar activity and cold/wet
climate episodes (see, e.g., review [91]). Fig. 4 confronts a physics-based reconstruction of the solar activity from the 14C data [69,87] with periods of identified sudden climatic shifts to cold/wet conditions in Europe during the last 7000 years [7,49]. One can see that they tend to appear during the grand minima periods.We note that 12 out of 14 climate shifts after 5000 BC occurred during grand minima of solar activity identified by Usoskin et al. [87], giving a 86% hit rate. On the other hand, only 3 (ca. 4200 BC, 700 AD and 1050 AD) out of 15 grand minima identified for the same period are not accompanied by climate shifts (80%hit rate). This also suggests, with high significance, a close relation between shifts of the climate type and solar activity (cosmic rays), at least in the European region. Although such studies cannot distinguish whether the primary effect is via CR or solar irradiation (e.g., [17]), an analysis of the geomagnetic field variation may help in disentangling the mechanisms (see a subsequent section).
In summary, there is a set of evidence that the solar variability affects the climate changes on centennial-millennial time scales, but it is hard to distinguish the role of cosmic rays, and the exact mechanisms need to be resolved.”
Well, we all know that mere correlation proves nothing, but a 86% hit rate may not be a coincidence only?
Timo,
I’m afraid I am a bit of a skeptic when it comes to GCR/solar variability and climate. First, trying to extract a periodicity from paleoclimate data is a little like trying to find a needle (a particular one) in a stack of needles. It’s rather like epidemiological studies in medicine–unless you have a theory to guide you, how do you guard against what we in particle physics used to call “bump hunting”. I’ve seen 4-sigma signals emerge from known background. Along these lines, you have to make a distinction between a priori predictions and a posteriori studies–you need a much more significant correlation for the latter to be statistically significant.
Space radiation is a part of my day job, so, I am somewhat familiar with efforts to reconstruct past solar history. They are quite problematic. Shea and Smart looked in detail at this, and I’m not sure even they fully believe their reconstruction. Certainly they take it with enough salt to risk raising blood pressure. Don’t get me wrong. It’s good work. Ilya’s paper (what little I’ve had time to read) looks good, too. It’s just that there are a lot of things that vary as the Sun varies, and without a detailed physical model, it’s very hard to avoid going down a lot of blind tracks.
I think this work is important–especially as we start trying to refine GCMs and make regional predictions (after all, availability of cloud nucleation sites probably varies a lot regionally). However, because clouds both warm and cool, I don’t expect that this work is going to revolutionize our understanding of global climate. We’ll still find that increasing CO2 increases the energy in the climate–and probably magnitudes will not change that much. Thanks for the link. Oh, btw, you might suggest to Usoskin doing a Monte Carlo study to determine statistical significance. I think it would be useful both for the Grand Max/Min paper (to see if the clustering around the “2nd mode” is significant) and for this paper as well (looking at how often “noise” with various characteristics returns a positive correlation.
Given wayne davidson’s posts, I’m curious about the next addition to this graph:
http://www.arctic.noaa.gov/reportcard/images/essays/atmosphere/figa1.gif
Will Nitschke, What “sides” of the debate are you referring to? Do you know of a single scientific society that has advocates a theory other than anthropogenic CO2? Do you know of any studies by climate scientists in peer-reviewed journals that suggest any well developed theory other than anthropogenic CO2?
Look, peer review is a floor. I recently reviewed an article that was absolutely incorrect technically, but still contained some interesting ideas and perspectives. Rather than reject the article out of hand, I took the time to make suggestions of things that needed to be corrected and additional work that needed to be done. It was my fervent hope that the authors would look at the mountain of work I had suggested and go away. They did not. Rather, they took most of my suggestions and the second draft was much improved. After 2 or 3 iterations, the article was still flawed, but much improved, and it still had the potential of sparking some interesting discussions. I noted the remaining flaws, but said I would not recommend rejection. My rationale is that my colleagues are big boys and girls and can spot crap in an article, and maybe someone can take the interesting ideas and foster discussion or develop them further.
An article doesn’t have to be perfect to merit publication. Also, some journals have higher standards of “perfection” than do others. I’m just curious where you are getting your ideas if you think current climate science is deeply flawed.
Ref 222 Timothy writes “Just out of curiosity, how quickly does land flow in Ottawa, and how big are the waves?” I am not aware that Newton’s Law of Cooling has different effects if one surface is water or land. As a matter of interest, the land is much warmer than the oceans, so it is more difficult for the frost to penetrate in Ottawa compared with the Arctic Ocean.
Jim Cripwell (#232) wrote:
You are forgetting the thermal inertia. Oceans have a great deal more of it than land does. However, you are right about snow. Works the same way with the ocean as it does with land. But there are some additional complexities involved. With ice, leeds form when the ice gets cracked. In the Arctic the will mean frost steam and the fissures will rapidly refreeze — something which actually works in your favor.
But then there is the fact that ocean water is especially dark. It is a good thermal radiator. I doubt the same can be said of ice. And there will be cooler layers of water which will insulate the warmer water below. Then there are the darker pools which form at the surface in the spring. That might drain away of course, but only once it melts through to bottom of whatever ice it is on.
First year ice will tend to have brine. As soon as it begins to melt, the brine goes first, and you are left with honeycombed “rotten ice” which is especially susceptible to mechanical forces and melt. Likewise, first year ice rarely gets more than three meters deep.
Finally, you will always have currents of water below, and stronger poleward currents of warm water have been more common in recent years, and convection will play a greater role in the spring. These aren’t sort of things you have to worry about with land.
RE:232
I think Timothy’s point was that ocean turbulence will slow down freezing. You can verify this in your back yard. Go outside with two buckets of water when the temp is less that 0C. Stir one constantly. Observe any difference in rate of freezing.
Of course, as you imply, the ‘thin ice is breaking up in storms” hypothesis is currently speculative, at least for you and I. Others may have the proof you requested, and I’d like to see it, too. E.g. Wayne Davidson(225) said “Current sat pics show numerous almost countless leads where the Arctic Ocean open water was in September.” Wayne, if those current sat pics are available for public consumption, maybe you could provide links?
It seems extremely likely that ice formed in the last couple of months or so over area that had been open sea is thinner than the multi-year ice . Can we agree on that much, Jim? Whether the ice is “thin” or “thick” depends on how we operationalize those terms. So the new ice may or may not be “thick” by your definition of that word, or mine, but perhaps we can agree that it is very likely thinner in the recently frozen areas than in the areas of multi-year ice.
If so, the next question is whether it is thin _enough_ to break up in storms like the recent ones, yes? And this is what you were really challenging in 213, yes? I.e, you question whether the ice is thin _enough_ to be “prone to rapid destruction by intense wave and wind action,” as per John in 209. John’s characterization of said ice as “very thin” is a matter of semantics, whereas the behavior of the ice under stress is an empirical question. If Wayne Davidson’s statement about satellite imagery showing lots of breakage in the new ice is accurate, then we have our answer.
About GHG>ocean and solar>ocean forcing, I’ve some questions:
– does an IR forcing and a SW forcing produce the same effect for ocean heat content ? (As IR doesn’t penetrate the water, but just warm the skin, we could imagine more IR radiation is used for evaporation at sea-air interface when compared to an equivalent SW forcing)
– is there a strong influence of IR forcing water vapor feedback on SST (on Tropics) ? (As water vapor feedback is mainly effective in higher layers of troposphere, and as near surface layers are already almost saturated on VE absorption band, we could imagine the WV feedback have not a strong influence on STT and oean heat content, at least in tropical zone)
Thanks for your answers.
Jim, incidentally when I said in 233:
I meant of course the rapid release of heat by frost steam works in your favor — but not the rapid refreeze of the fissures. However, we will know soon enough. Just seeing how early spring returns to the Arctic should tell us a fair amount.
some info on sea ice from nsidc, and my thoughts (http://nsidc.org/seaice/intro.html):
“generally, the top 100 to 150 meters (300 to 450 feet) of water must be cooled to the freezing temperature for ice to form.”
-This is largely because as the surface water gets colder, it gets denser, and sinks away from the cold air. This is something that the ground in Ottawa (and elsewhere) doesn’t do.
“multiyear ice: ice that has survived at least one melt season; it is typically 2 to 4 meters (6.6 to 13.1 feet) thick and thickens as more ice grows on its underside.”
-So if the multiyear ice is typically 2 to 4 meters thick, it’s likely that ice less than two months old in the same general environment is less than 2 meters thick. How much less? I’m still learning. But there’s a lot of good info at NSIDC about the process. New ice starts as crystals here and there in the water, progresses to slush, and then gains rigidity over time. So it’s not like fresh water freezing on a still pond. Once (relatively) rigid it’s apparently still shot through with little droplets of high-salinity brine. So it seems to me that however thin or thick it is, it might also have less structural integrity than old ice. But as I say, I’m still learning.
Just for the record, the data is in from NSIDC on average values of sea ice extent in the arctic for November. (OK OK it’s surface area not volume). 2006 data Oct 8.3 million sq kms, Nov 9.9. 2007 Oct 6.8 Nov 10.1. Paging Nick Barnes and Joe Duck. I will freely admit I did not expect that sort of dramatic turn around.
RE # 237
Kevin: you said
[Once (relatively) rigid it’s apparently still shot through with little droplets of high-salinity brine. So it seems to me that however thin or thick it is, it might also have less structural integrity than old ice]
That was another aspect of new ice I had not considered. And, it might add to explaination of how the ice surface diminished between Nov. 27 and Dec. 3 ( time in which cyclone(s) evidently swept into the Western Arctic).
See the following images from Cryopshere Today.
Dec. 4: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20071204.jpg
Nov. 27 http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20071127.jpg
What is the ocean depth typically used to divide the surface waters from the deep ocean? Is it as much as 300 meters?
” I will freely admit I did not expect that sort of dramatic turn around. …” – JIm Cripwell
You weren’t expecting winter?
Will the perennial ice continue to get younger? I think that answer may be as important as extent.
Timothy Chase 211
Shattered? Perhaps, if you hold your monitor upside down. Not only is the thick black line clearly 1C below the holocene maximum, but every single proxy was at one point higher than today. And, around 140 thousand years ago the Vostok and Epica ice cores “show” the Earth was at least 3C warmer than today.
Also, you state in 165,
With this in mind, could you please explain the independant lines of evidence for the amount of aerosals in the atmosphere from say 1940-1970.
#237, Kevin, the problem with Polar orbiting NOAA shots is that they change every 40 minutes, one picture may show myriad of leads, the other clouds,
then try on a regular basis, especially in the afternoon :
http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg
I saved one picture but RC doesn’t allow pic displays.
There is no fixed link. Great stuff in #223 by John, water didn’t only reappear over the Arctic Ocean , important areas of open water resurfaced around Cornwallis Island after an intense blizzard as well.
Re #238: Jim, if you look around the NSIDC site for the relevant material you’ll find that scientists expected it. The Arctic Ocean will need to warm up a fair amount more before it will be able to resist ice formation through the months of little or no sunlight. It’s a pretty standard denialist ploy these last few years of sharply lower summer ice to make claims that winter re-formation of the ice is somehow unexpected and then to try to make hay when things go as predicted. Don’t fall for it.
Ellis (#242) wrote:
No. Shattered – at least within the Holocene. The past 10,000+ years. Longer than human civilization has been around. If you read the text, the colored lines represent local temperatures. The black line is the average of these — a “proxy” for the global temperature. The black arrow up at the top left? It says 2004. I believe that’s us, more or less. Shattered.
However, you are right about the past half million years, more or less – qualitatively speaking, at least. I shouldn’t have said “If I remember correctly…” because clearly I didn’t. Judging from sediments, there appear to have been two times in the past 2.5 million years when temperatures were higher. What you point to 140,000 years ago was one of them. Another was 400,000.
Both times, the two locations would seem to have been virtually in sync. Other times when one was especially high they were slightly out of sync, enough that it would appear that the global average was still below what it is today.
Polar amplification implies that however much they were above present temperatures for those locations, you would want to divide that by two to come up with the extent to which the global temperature was above the current global temperature. So globally we are looking at more like 1.5 C above where we are now — and even if we stopped CO2 emissions today, temperatures would continue to rise for several decades. But CO2 emissions have actually been considerably higher since 2000 than they were during the 1990s.
*
For sediments as well as estimated temperatures of both, check the following:
http://www.globalwarmingart.com/wiki/Image:Five_Myr_Climate_Change_Rev_png
*
Ellis quotes me from 165:
Ellis (#242) wrote:
We are talking about sulfates and sulfides, mostly. Nitrates, too. Some organic carbon.
For sulfates, you might check:
Anthropogenic signals recorded in an ice core from Eclipse Icefield, Yukon Territory, Canada
Kaplan Yalcin and Cameron P. Wake
Geophysical Research Letters, VOL. 28, NO. 23, PAGES 4487-4490, DECEMBER 1, 2001
Sulfate trends in a Col du Dôme (French Alps) ice core: A record of anthropogenic sulfate levels in the European midtroposphere over the twentieth century
Journal of Geophysical Research, VOL. 106, NO. D23, PAGES 31,991–32,004, 2001
… and if you want more sources or more information on how they try to estimate the levels and forcings for aerosols, you might try:
Air Pollution as a Climate Forcing: A Workshop
Day 2 Presentations
What Relevant Information is Provided by GAW Stations, Ice Cores?
Urs Baltensperger
http://www.giss.nasa.gov/meetings/pollution2002/d2_baltensperger.html
… but remember that it is current only as of 2002.
Re: 188 Martin Vermeer. Thanks for the reference. Just looked at the abstract but it looks like GCM modelling. I guess what I am getting at is that Lindzen and now Spencer are having to do really complex work with radars and satellites to try and determine the influence of rising sea temperature on cirrus clouds in the tropics. They suggest that the feedback is negative but nothing they do is conclusive. The obvious question is what conclusive proof do we have of the opposite – that the feedback is positive? Have people done the work with radar and satellites to prove that the feedback in the tropics is most likely positive?
Re: 207 Timothy Chase. …But there is only one problem…
I think you are saying that Spencer’s work is not conclusive. Fair enough but, as I said above, how have we proven that the converse is true? How have scientists proven that the effect of rising sea temperatures in the tropics on cirrus clouds is a positive feedback? I am hoping that it is not just an assumption made in the GCMs.
Ellis, talking about the Holocene — last ten thousand years or so —look again at the picture you think you’re describing, you’re not seeing what’s right on the page there.
Look at the left side. See the big black arrow labeled “2004” there? Then look at the little inset square that expands the last few years. See the temperature?
http://en.wikipedia.org/wiki/Image:Holocene_Temperature_Variations.png
You’ve fallen into a mistake often made looking at these very long time series charts — recent years are too narrow and steep a line to tell from the frame around the picture.
The recent — fast — temperature change is shown up to 2004. But only on the inset, it’s just a vertical line at the side of the frame on the long time series picture. Compare the position of that arrow — that’s the current end of the ‘big black line’ you claim to be comparing across eight thousand years.
Seriously, look, slowly, carefully, at the chart there.
How does that line from the movie go? “Who’re you going to believe, the chart or your lying eyes?”
Ellis, make sure you look back at the edits on that Wikipedia page, it appears someone’s been mucking with it. I didn’t review all the changes but just comparing it to William Connolley’s last text, for example, someone over the last handful of edits for example changed:
WC: “Of 140 sites across the western Arctic, there is clear evidence for warmer-than-present conditions at 120 sites.”
to this current nonsense word salad line:
“At 140 sites across the western Arctic, there is clear evidence for warmer-than-present conditions at 120 sites.”
When someone who can’t write gets into Wikipedia, this happens.
Oh, wait, I went to bed hours ago, I’m sleepwriting. I got the Wikipedia edits backwards. Well, I was right about the chart temperature for 2004. Memo to self, preview is for a reason …
Jim Cripwell @ 238: Just for the record, the data is in from NSIDC on average values of sea ice extent in the arctic for November. (OK OK it’s surface area not volume). 2006 data Oct 8.3 million sq kms, Nov 9.9. 2007 Oct 6.8 Nov 10.1. Paging Nick Barnes and Joe Duck. I will freely admit I did not expect that sort of dramatic turn around.
I did.
https://www.realclimate.org/index.php/archives/2007/10/sweatin-the-mediterranean-heat/#comment-62656
https://www.realclimate.org/index.php/archives/2007/10/the-certainty-of-uncertainty/#comment-62937
https://www.realclimate.org/index.php/archives/2007/11/did-we-call-it-or-what/#comment-66076
CT measures area, not extent, which accounts for the slightly different timing of the rapid freeze.