Talk:Solar variation

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[edit] Constant rate

Thanks for adding some actual science to this article, William!

The rate of reactions is sufficiently constant that the amount of solar radiation emitted at the surface does not change much. The variations in total output are so slight (as a percentage of total output) that they remained at or below the threshold of detectability until the satellite era, although the small fraction in ultra-violet wavelengths varies by a few percent. Total solar output is now measured to vary (over the last two 11-year sunspot cycles) by less that 0.1% climate/solar.htm.

I'm so tired of ignorant hacks (like me ;-) just pasting in poorly-reworded summaries of popular articles or propagandistic advocacy pieces!! --Uncle Ed 14:29, 10 Aug 2004 (UTC)

(William M. Connolley 21:40, 10 Aug 2004 (UTC)) Hey, you said it :-) Anyway: re Spencer Weart: firstly I don't think this belongs here, at the front (I would move it but can't at the moment). Connection to sfc T is the only reason you (or I, to be fair) care about solar var, but its not its primary characteristic. Secondly, what you quote is *history* from 1975! Wiki should be presenting the present-day opinion. Oh, and I changed the quote style at bit.

History is interesting. If someone makes predictions and they keep turning out right, I'm going to spend more of my valuable time studying what _he_ says, rather than someone whose predictions mostly turn out wrong. So Stephen Schneider who was moaning about global cooling less than 30 years ago, and Paul Ehrlich with predictions of scarcity and starvation, earn less credibility in my book. And when they start endorsing the "Chicken Little" of the moment, Michael Mann, it makes me want to have someone doublecheck Mann's research. --Uncle Ed 14:33, 13 Aug 2004 (UTC)
(William M. Connolley 15:20, 13 Aug 2004 (UTC)) SS is often misrepresented. Try www.wmconnolley.org.uk/sci/iceage if you haven't before.
Can't see the relevance of Ehrlich
Calling Mann a chicken little is a grosss pointless insult and you should be ashamed - you wouldn't call anyone on wiki that.
Lastly: yes history is interesting. In various places though you've been putting in history (eg 1990 ipcc) as though it were representative of current opinion. History goes in a section marked history.
  • I hacked in a poorly worded summary of the history of the field, instead of the cryptic mention by Weart of solar+aerosol study. Weart's quote is in his already-linked-to "Discovery of Global Warming" page. I relabeled the entry for that link. Oh, and Uncle Ed, thanks for having the doublecheck done. (SEWilco 19:49, 21 Feb 2005 (UTC))

[edit] Referencing

I don't understand what's going on with the recent spate of reversions - surely references at end using templates are better than inline refs? Enochlau 10:52, 2 October 2005 (UTC)

Wouldn't it be better to discuss *before* taking sides in that case? No, inline refs are better - they are one click not two. William M. Connolley 14:33, 2 October 2005 (UTC).
I'm not taking sides unilaterally. It's Wikipedia style guidelines: see Wikipedia:Footnote3. Enochlau 16:43, 2 October 2005 (UTC)
There is no consensus on that - there is a dispute in progress as to whether it chould be done on or not. William M. Connolley 18:27, 2 October 2005 (UTC).

I don't know the status of the footnoting debate, but the edit I just reverted did not make a footnote - just put the URL inline rather than as #1. I see the edit comment rv WMC's destructive wiki edit as inflamatory and uncalled for. If SEW wants to use an as yet poorly defined footnote style, then make the ref in question #1 in the footnote list. I feel inline references (with a list of refs at the end) preferable as well as much easier to use and manage by future editors to the page. I have experimented with the style SEW wants to use here in other articles and found it cumbersome. Let's keep the edit comments civil, please. Vsmith 20:57, 2 October 2005 (UTC)

WMC's edit did use destructive wiki code which goes against policy and guidelines. (SEWilco 02:32, 16 October 2005 (UTC))
I'm not saying that inline references are bad - they're better than nothing. If you want to use them, please do not make the entire url appear - shrink them into, say, [1]. Enochlau 23:15, 2 October 2005 (UTC)
My point exactly. And a weakness in the footnote3 system as any innocent (or otherwise) insertion of a good inline reference messes up the footnote3 numbering - quite a serious flaw it would seem - makes for a high maintenance problem. As for SEW's last revert, why not make the link #1 in the refs - it is a valid and used reference? Has the use of footnote3 been discussed and agreed on here - or is it just a bold decision by one editor - why not discuss? Vsmith 00:49, 3 October 2005 (UTC)
Let's come to some sort of consensus then. I suggest using footnote3 consistently for just about everything since most of the article already uses it anyway. Enochlau 01:13, 3 October 2005 (UTC)
The footnote3 system is cumbrous and unmaintainable. Adding a new ref in destroys it. It is not acceptable to forbid adding any new [url] style links into the page, as SEW is trying to do. Wiki is supposed to be *simple* and easy to use, and should not force you into over-elaboration. William M. Connolley 08:41, 3 October 2005 (UTC).
There is a recommended style for inline links, which you chose to not follow. I converted the inline links to use more complete Footnote3 citations. (SEWilco 17:33, 3 October 2005 (UTC))
Hardly anyone follows it, for the obvious reasons, mentioned above. William M. Connolley 20:24, 3 October 2005 (UTC).
There is a reason why they exist; no one wants to make it more difficult. Sometimes books or other offline resources are used as references; e.g. "Henrik Svensmark (1998). Influence of Cosmic Rays on Earth's Climate. Physical Review Letters 81 (22): 5027-5030". This is not possible without footnoting. Using the footnoting system is not difficult - sure, it takes two edits instead of one, but it's not that much more difficult. Also, if you ever want this article to be featured, it will need to use footnoting. If you find the current mish-mash of styles annoying, wait until the weekend and i'll sort it out. Enochlau 08:58, 3 October 2005 (UTC)
Sorry, I will oppose featured article status, that usually makes an article worse.--Silverback 09:19, 3 October 2005 (UTC)
What?? I don't understand you guys. Enochlau 10:04, 3 October 2005 (UTC)

We're not talking about books. These are inline refs to web pages. Introducing a cumbrous system that makes it impossible to add new refs without re-numbering all the exising ones is unmaintainable. Your point about FA is bizarre: if true, its a huge hole in the FA system, but I suspect you're simply wrong. FA need good refs, not to use the broken fn3 system. William M. Connolley 15:11, 3 October 2005 (UTC).

Then how do you suggest we reference offline material? (Note that there is at least one offline reference in the existing footnotes.) Inline them too? Ridiculous. Enochlau 15:56, 3 October 2005 (UTC)
In the few cases where we're referencing offline material, then I guess you have to fall back on the unsatisfactory footnote style. But the vast majority are to online material so we don't have to use it. William M. Connolley 20:06, 3 October 2005 (UTC).
So all that an online material citation requires is a URL, with no title nor author information? Online material such as [1], which only states that I have to log in. Until I log in I don't know if it is worth paying to see whatever it is. Assuming, of course, that it is not a dead link. (SEWilco 20:47, 3 October 2005 (UTC))
"something must be done. this is something. therefore it must be done". Its obvious nonsense, and so is trying to use such a cumberous system. If we had a nice system that was easy to use and dealt well with adding new ones, then great. But we haven't got that. William M. Connolley 21:00, 3 October 2005 (UTC).
Footnoting is generally problematic on wikipedia; there is an alternative system (in use at eg George Galloway) which allows mixing inline and footnotes without too much confusion. Not ideal, but less bad than some of the other footnoting systems. Rd232 21:35, 3 October 2005 (UTC)
I just took a look-see at that article and the current problem here would be solved if that have it both ways approach were adopted here. Does it have a name - like the footnote3 thingy? In my earlier experimenting w/fn3 I was dissapointed by the potential for the kind of disruptions we see here - one in line link messes it up. Vsmith 22:44, 3 October 2005 (UTC)
This was the reason I created Template:NamedNote a while ago. But I notice now that it seems that approach has been (sort of) integrated into footnote3, so probably better to look at Template talk:Ref for the possibilities there. Ref_num looks like it does the same job. Rd232 06:59, 4 October 2005 (UTC)
I agree that footnoting is a problem; some of the discussion pages in fact talk of building it into the mediawiki software in the future. In the meantime, we need to come to a satisfactory resolution. I don't mind the style they have at the George Galloway - it's not ideal as the numbers need manual editing which is always undesirable. However, SEWilco has a point - web pages are just like offline references in a way - if you're writing an essay, wouldn't you put in author/title/retrieval date, especially for these newish areas of science? I'd vouch for the footnote3 system because, even though there is currently no concensus, the discussion there notes that it is future-proof - any future system should be able to read it in and convert it. Enochlau 23:46, 3 October 2005 (UTC)
Future proof is wonderful. But the fn3 system isn't present-proof (to repeat the point you've missed: its too cumbersome; its unmaintainable). Look around the global warming type articles - there are lots and lots of inline links, and the *only* fn3 links are those put in by SEW because its his pet system. William M. Connolley 09:21, 4 October 2005 (UTC).
How exactly is {{ref|blah}} and then {{note|blah}} at the end so much more difficult? The main problem here is that there are two starkly opposing sides and this edit war is going to go on until the sun dies. A compromise, somewhere in between, is to use the {{NamedNote}} system, but you don't seem to like that either. Enochlau 09:59, 4 October 2005 (UTC)
If its so easy, why are you making edit commments praising the "lot of work" that you think SEW did? Please at least try to be consistent. The point is that adding refs using [url] is easy. Its also easy to use them as a reader: click on them and you're there. The fn3 system is hard work (even you admit that) and takes two clicks to get to. Its silly. Also somewhat unexplained is your sudden interest in solar var. William M. Connolley 10:39, 4 October 2005 (UTC).
You misunderstand me. I've never said that fn3 is hard work - however, converting an entire page with tens of them is work to be congratulated. In some cases, it's less work - I can click on it, see the title and decide whether to proceed. My sudden interest in solar variation? What does that have to do with you? For the record, I am an undergraduate who has done physics so I like reading this kind of stuff; I came here via global warming articles. Enochlau 12:37, 4 October 2005 (UTC)
Footnote3 links function despite the mismatching numbers caused by careless or destructive editors. The more complete citation information which tends to be used in references is more encyclopedic and robust than a bare inline URL. The numbering problems are a side effect of current Mediawiki limitations. (SEWilco 15:48, 4 October 2005 (UTC))

[edit] Detailed citations policy

Wikipedia:Verifiability policy prefer more detailed source references over less detailed. William M. Connolley has been destroying more detailed source entries due to being "icky". Which policy covers "icky"? (SEWilco 02:32, 16 October 2005 (UTC))

I guess some people are just allergic to references like others are to hayfever. If there continues to be a problem, you might like to consider Wikipedia:Mediation, but we'll see. Enochlau 07:45, 16 October 2005 (UTC)
You are trying to use a variety of inapplicable policies to bludgeon in your pet project, ignoring their problems, and the difficulty of working with these things (which is presumably why you have to litter the page with instructions on using them). William M. Connolley 10:04, 16 October 2005 (UTC).

[edit] Table of events

The table of events is currently:

Solar activity events and approximate dates Event  Start   End
Oort minimum    1040    1080
Medieval maximum (see Medieval Warm Period)     1100    1250
Wolf minimum    1280    1350
Spörer Minimum  1450    1550
Maunder Minimum         1645    1715 
Dalton Minimum  1790    1820

I'm curious about the first two (and perhaps the third). They can't be read from the graphs on the page and I can't see any other source. Where is the info from? The Oort min is smack in the middle of the MWP period, incidentally. William M. Connolley 16:06, 31 October 2005 (UTC).

[edit] Other factors

What should be in the global warming / climate change section is a link to Axial_tilt. That and the related Arctic_Circle and Antarctic_circle need a bit of numbers disambiguation on the variation in how much Earth's axial tilt changes.

Climate change is driven by BOTH variations in solar output and the continously varying tilt of Earth's axis, which at present is decreasing. Think about the effect that has on the amount of surface area that's in constant darkness from 24 hours to six months per year, and how that affects the net heat loss.

There already is a section about Milankovitch cycle variations. (SEWilco 15:19, 11 December 2005 (UTC))

[edit] gw section

The entire GW section is poor, presenting marginal research with far too much priority. The Mainstream view isn't presented at all!

I cut out all the S+V stuff. It looks like it wsa put in by people who hadn't even read the papers. So I cu:

In 2003, Shaviv and Veizer compared a temperature reconstruction of the last 500 million years to expected changes in cosmic ray flux as the solar system moves around the galaxy. They concluded that, at least over very long time scales, cosmic ray variations had a much larger impact on climate than other processes (such as greenhouse gas changes) [2]. Since, as described above, cosmic rays are also affected solar variations, their work may imply a larger role for solar variability in recent climate change than has previously been appreciated. Also, by looking at the temperature changes not ascribed to cosmic rays, they estimated that the climate response to doubling CO2 is only about 0.75 °C as compared to the 1.5-4.5 °C reported by the IPCC [3]. However, long-term processes occurring over millions of years may make it impossible to interpret of Shaviv & Veizer's results over the short time scales relevant to recent warming. [4].

Firstly, most of this has little to do with GW. Secondly its all marginal. Thirdly Also, by looking at the temperature changes not ascribed to cosmic rays, they estimated that the climate response to doubling CO2 is only about 0.75 °C doesn't seem to be supported by the paper: what it *does* say is In summary, we find that with none of the CO2 reconstructions can the doubling effect of CO2 on low-latitude sea temperatures be larger than ~1.9 °C... which is somewhat different, no? And since global ch is larger than tropical, what they find is entirely *con*sistent with IPCC. Fourth its not clear than such far-past stuff (different continents etc) is terribly relevant.

I also took out:

In 2005, Shaviv extended the analysis to several different time scales including historical 11 year solar cycle data, and concludes that solar activity accounts for 0.47 +- 0.19 degrees C (almost two-thirds) of the 20th century warming.[5]

This is a bit better, but still misrepresents the paper. William M. Connolley 17:38, 4 February 2006 (UTC).

It was Singer that provided the translation of the low latitude figure to a global approximation here[6]. Probably to make Shaviv's contrasting of his results with the 1.5-5.5 figure equivilent. How is the second paper marginal or misrepresented, or not relevant to global warming? The past stuff is relevant because it is data, the second paper makes it more relevant by showing that shorter time scales confirm the longer, thus making them mutually consistent and confirming, reducing concerns about the time scale differences.--Silverback 18:11, 4 February 2006 (UTC)
Ah well, if it was Singer, that explains why it was junk - what else would you expect? S+V is all marginal - in the sense of being way-out-on-a-wing-by-themselves. But you won't be able to hear that. William M. Connolley 10:18, 7 February 2006 (UTC).
It is easy for you to express your opinion, but can you support it with citations? S+V are managing to answer any criticisms of their theories with peer reviewed publications. Why not just balance reports of the research in this article with citations, rather than just reverting based on your opinion?--Silverback 05:28, 22 March 2006 (UTC)
The junk of Singers that you cited is too marginal - why would anyone write up a peer-rev rebuttal. Only the skeptics take him seriously enough to read it. S+V - yes, we should balance this, and the weight-of-lit is that there stuff is marginal. You always get "interesting" papers published, the mistake is to think that each new paper deserves a mention. You need to give up defending - or really, even bothering to read - Singer, if you want to be taken seriously William M. Connolley 09:46, 22 March 2006 (UTC)
In other words you don't have any cites just your opinions. This is about S+V's published works, not about Singer. S+V's theories cannot be ruled out as alternate explanations of the evidence, and that is why they can get published. They've extended their work to show that the shorter time scales are consistent with their theories. I only mention Singers translation to put their results in perspective. Solar variation through indirect effects are still a viable alternative theory and the best way to rule it out is with evidence and not suppression. If the solar signature were on the climate were not so strong, and understanding of the complex non-linear climate and cloud physics were better, then there would not be all this evidence pointing to so kind of indirect influences of solar activity. The evidence demands a mechanism and S+V's work is one of the leading theories for that mechanism. The others should be documented as well, including the denials that there is this strong solar signal. But you should not be doing the denying, except here on the talk page where it is fine, but in the article your proper response is citations and not suppression and reversion.--Silverback 11:51, 22 March 2006 (UTC)

[edit] Graphics

There were some poor quality charts, often reszed screenshots from PDFs. I've tried to, where possible, collect the relevant raw data from publically available sources and reproduce the graphs. Please feel free to revert if they aren't of appropriate quality. I do have some issues with the Hallstadtzeit cycle chart - once I detrended the data I still didn't get anything much akin to the claimed 2000 year cycle - there are some general periodic trends but they are far from clear as the caption (which I didn't change significantly) states. I also have some issues with the Carbon/Sunspot graph. There simply doesn't appear to be any really significant correlation even with the claimed 20 to 60 year delay. What am I missing? Leland McInnes 03:52, 7 February 2006 (UTC)

Some points:
  1. If you are creating a replica image to replace one of low quality, it is a good idea to either include a link to the previous figure in the image description or to upload it with the same name so that the new figure automatically replaces the old (of course this is only possible if the same image format is used). If you do upload a new version over the old, the old version will be available in the file history section of the image description.
  2. I would suggest using INTCAL04 rather than INTCAL98, and note that the final point is not real data but some sort of end of record place holder. Since the invention of nuclear weapons, carbon-14 has been contaminated by man-made sources, which is why those data end circa 1950.
  3. I am going to revert the Hallstadt cycle plot, since your figure is qualitatively different than the published result and I don't know why. If I had to make a guess, I would suggest they used a band pass filter whereas your figure suggests some sort of moving average or polynomial fit.
  4. It's not a 20-60 year delay exactly, the residence time of carbon in the atmosphere is several decades, which causes terrestrial records to average over the short-term variability in production. So in essence, one is really only trying to say that the broad wiggles in carbon variation match the large scale changes in solar activity. As an intellectual exercise, one could try taking a moving exponential average of the sunspot activity with a multi-decadal time constant and seeing how well they agree. However, I would not generally encourage you to add such an average to the figure.
Dragons flight 04:58, 7 February 2006 (UTC)

[edit] 1470?

AFAIK the 1470 year cycle (Braun?) is only proposed, not an observed cycle. And why was the 2.3kyr cycle removed? Also the periodicity of D-O events is not by any means certain: controversial would be better William M. Connolley 13:08, 19 March 2006 (UTC)

Sorry, didn't mean to remove the 2.3kyr cycle. The 1470 year cycle is the same as the 1500 year DO periodicity. The Braun paper published in Nature makes the case that the actual periodicity is 1470. Of course since the identifying events usually involve the flipping of modes, it isn't 1470 like clockwork, but they sometimes flip early and sometimes late, but the 1470 can be seen as the attractor. Braun confirmed via modeling that the shorter cycles reinforce at this 1470 year period.--Silverback 13:57, 19 March 2006 (UTC)
And are you claiming that the 1500/1470 y cycle is actually observed in solar output or anything like that? And please stop talking abpuot D-O "periodicity" as if it were settled fact: it isn't William M. Connolley 15:47, 19 March 2006 (UTC)
It is a theory that is supported in the literature due to evidence seen in the climate and solar output proxies, and the citation from the recent Nature article is further support for that theory. I wasn't aware that the cycles already cited were factual and not theorectical. There is probably very few of the cycles have actually been observed for more than a few cycles beyond the 22 year cycle. The Nature article is a good place to start, since its references will lead you to other published support. In GW you have supported having climate model predictions in the article (I support that too), despite their not being settled fact, why are you applying a different standard here? This latest article is climate model based confirmation of this solar cycle mechanism for the increasing body of evidence for this periodicity.--Silverback 05:57, 20 March 2006 (UTC)
If you don't have access to the full text of nature, perhaps you have access to this editorial summary.[7] I think these like the abstracts are available free.--Silverback 06:40, 20 March 2006 (UTC)
Here I quote the last two paragraphs of the article:
"A key aspect of our concept is that the events are triggered by very sharp peaks in the forcing, with duration of only decades. This can explain the puzzling regularity in the timing of DO events in the Greenland data, which were reported to deviate by no more than ,10% from exact multiples of 1,470 years15. If the events were triggered by broad peaks (for example by some sinusoidal-like forcing cycle of a 1,470-year period), much larger deviations from exact timing would be expected in the ‘noisy’ climate system. Hence, the exact timing of the more recent DO events (ages between 10,000 and 50,000 years) is a strong observational indication that they are synchronized by shorter cycles."
"We have demonstrated that a coupled ocean–atmosphere climate model can reproduce DO events with a robust spacing of 1,470 years when forced by the superposition of two freshwater cycles with much shorter periods near 87 and 210 years. A frequency of 1,470 years is therefore not found in the forcing; it is found only in the model response. We illustrated that this frequency conversion between forcing and response is a plausible consequence of highly nonlinear dynamics inherent in the simulated DO events. Our results indicate that the observed 1,470-year climate cycle could have originated from solar variability despite the lack of a 1,470-year spectral contribution in records of solar activity.Moreover, the 1,470-year climate response in the simulation is restricted to glacial climate and cannot be excited for substantially different (such as Holocene) boundary conditions; for these, the model response shows the frequencies of the applied forcing (,86.5 and 210 years), as also documented in various climate archives22,23,30. Thus, our mechanism for the glacial ,1,470-year climate cycle is also consistent with the lack of a clear and pronounced 1,470-year cycle in Holocene climate archives."
--Silverback 07:17, 20 March 2006 (UTC)
Subscription not needed!! The paper itself is available online.[8]--Silverback 07:37, 20 March 2006 (UTC)
Here is a quote from an independent 1994 extrapolation based only on the current superposition of these two cycles " Extrapolation into the future of two cycles evident in the 14 C record, at 208 years (the Suess cycle) and 88 years (the Gleissberg cycle), suggests that the increasing solar activity that has followed the Maunder Minimum may continue into the early twenty-first century (Damon and Sonett, 1991), with a decline commencing around 2040. But extrapolation of these cycles into the future and prediction of solar effects is a highly questionable procedure, given our lack of knowledge of the fundamental processes involved (see Chapter 6). " Solar Influences on Global Change (1994) Commission on Geosciences, Environment and Resources [9]--Silverback 07:47, 20 March 2006 (UTC)


OK, well first off lets quote from your quote: Moreover, the 1,470-year climate response in the simulation is restricted to glacial climate and cannot be excited for substantially different (such as Holocene) boundary conditions; for these, the model response shows the frequencies of the applied forcing (,86.5 and 210 years), as also documented in various climate archives22,23,30. See how that effectively rubbishes Singers 1500 y stuff?

Now, we also have from the paper: But whereas pronounced solar cycles of ,87 and ,210 years are well known8–12, a ,1,470-year solar cycle has not been detected8. This means that whatever the virtues of this stuff, we *should not* be listing a 1470y solar cycle in "solar variation" - because even this paper admits its not there.

And lastly, I see you've totally ignored my And please stop talking about D-O "periodicity" as if it were settled fact: it isn't, which is irritating. Its Rahmstorfs theory mostly. He's a good chap (of course) but that doesn't mean we take his word as gospel (as you would no doubt say were I to paste in some of his opinions on GW as fact).

William M. Connolley 12:45, 20 March 2006 (UTC).

I have totally ignored your please stop talking about D-O periodicity. The peer reviewed paper in Nature had no problem talking about it: "The onset of successive Dansgaard–Oeschger (DO) events, as documented in Greenland ice-cores1,2 for example, is typically spaced by ,1,470 years or integer multiples thereof13,14. Because deviations from this cyclicity are small, often less than 100–200 years15, external forcing (solar or orbital) was suggested to trigger DO events6,15,16." I don't think "periodicity" is that far off from "cyclicity" but I can use the latter word if you prefer.
The statement you reference does not rubbish Singers 1500 year stuff. The periodicity in the climate response is marked in the glacial record because of mode changes in the climate. The fact that during interglacials the mode changes don't occur, does not mean the superposition of the shorter solar cycles resulting in peaks of forcing at every 1470 years does not occur. It only means that the mode change does not occur. But the 87 and 210 year cycles are well established even in the Holocene climate, so their superposition will also exist in the Holocene. Perhaps it is non-traditional to list 1470 among the solar cycles, because it is a multiple of the smaller cycles, but it exists just as multiples of the other cycles exist. If there is a 22 year cycle, there is also a 44 year cycle, etc, but we refer to all of these as the 22 year cycle. Similarly the peak in forcing from the prime multiples of the shorter cycles also exists (17x86.5 and 7x210).
The proper place for this, is both here, because the periodicity is not thought to be due to solar variation (the shorter cycles) and in the Global warming article, because this paper reinforces the importance of these shorter cycles in driving climate variation. Note, that superpositions of peaks and minima of these cycles have also been implicated in the maxima and minima in the climate record of the last millenium, even if the 1470 signal has not been specifically identified. There are other levels of reinforcing superposition than just this particularly notable 1470 year peak.--Silverback 09:37, 21 March 2006 (UTC)

Ah. Well, that makes one particular decision rather easy William M. Connolley 10:08, 21 March 2006 (UTC)

Evidence and a thorough explanation usually do.--Silverback 13:56, 21 March 2006 (UTC)


I've been trying to figure out how to comment on this. Let me start by saying that I think Rahmstorf's 1500 year clock with some skipped beats does appear to be a statistically robust and surprising feature of the data. Enough so, that it may require some sort of explanation. What that explanation may be, I'm not prepared to speculate, except to note that a variety of astronomical and terrestrial possibilities exist for which there is very little evidence. [Though Bond's cosmogenic isotopes are probably the most interesting of what limited evidence does exist.]

On the more specific issue of Braun et al.'s explanation. Their work depends sensitively on assumptions about the stability and amplitude of solar cyclicity, and the dynamical characteristics of DO events. I consider several of their assumptions to be highly implausible and therefore, in my professional opinion, I regard the work as a whole to be very unlikely to be correct. I note that the paper is only a few months old, and at least this far there hasn't been a published criticism of it (as far as I am aware), but I would encourage people to treat it with a healthy dose of caution and scepticism. Dragons flight 19:38, 22 March 2006 (UTC)

[edit] Opinion on solar variation and terrestial temperature

Cut passage:

To reconcile theories of an increase in solar radiation with the measurements would require other changes either in the spectrum of the sun (which has not been observed) or in the absorption profile of the atmosphere, which would probably imply some kind of climate change.

This argument is unsourced, and ignores the work of scientists Joanna D. Haigh and Sallie Baliunas. The intensity of sunlight reaching the earth correlates with sunspots. --Uncle Ed 18:46, 26 January 2007 (UTC)

[edit] Hale Cycle

[edit] Hale Cycle

The solar periodic activity is described by the Hale cycle and can be represented by a formula

Y = 100[Cos(2π/3 + 2π(t-1941)/(2х11.862) + Cos 2π(t-1941)/19.859 ] Image:Hale-cycle.gif

Or in a somewhat modified form:

Y = 100 abs [Cos(2π/3 + 2π(t-1941)/(2х11.862) + Cos 2π(t-1941)/19.859 ] Image:Formula.gif

The absolute value is plotted against the numeric values of the existing sunspot records for the period 1750-2006.


Further reading:Evidence of a multi resonant system within solar periodic activity

LANL - Los Alamos National Laboratory, USA [10]

[edit] What is solar forcing?

Solar forcing redirects to this page. Everywhere that this page uses the phrase solar forcing it is with the clear idea that the reader understands the term, but it is never defined. 71.112.17.22 23:51, 1 February 2007 (UTC)

Oops. Forgot to log in when I asked this question. pcrtalk 23:53, 1 February 2007 (UTC)

[edit] Challenges are shown in the efforts of Charles Greeley Abbot...

What challenges? What does this mean... could it be rephrased slightly for the hard of understanding, regards sbandrews 22:13, 25 February 2007 (UTC) ty sbandrews 19:51, 1 March 2007 (UTC)

[edit] Solar cycle length and global warming

Do any of the scientists contributing to this page have access to the scientific papers exploring the relationship between solar cycle length and terrestial average temperature? --Uncle Ed 19:38, 13 March 2007 (UTC)

Yes. The information on this page is rather skewed. It repeatedly mentions Laut's attacks on Friis-Christensen but not F-C's rebuttals. F-C says that it is Laut's papers that are full of errors. In the literature youy can find several papers that support the link (and several that dont). Paul Matthews 18:16, 23 March 2007 (UTC)
As I read it the only thing confirming the statement the sensational agreement with the recent global warming, which drew worldwide attention, has totally disappeared is the attackt by DamonLaut. Shouldn't it be possible to include the Henrik Svensmark defense[11]? That way readers can judge for themselves who to believe.--ElThyge 07:47, 25 July 2007 (UTC)

[edit] Balance

Stott's rejoinder was cut from the article:

In 2003, Stott et al found that "current climate models underestimate the observed climate response to solar forcing over the twentieth century as a whole, indicating that the climate system has a greater sensitivity to solar forcing than do models." and concluded that "The best estimate of the warming from solar forcing is estimated to be 16% or 36% of greenhouse warming depending on the solar reconstruction."[25]

I didn't understand the horribly unbalanced part of the edit summary. [12] Isn't Journal of Climate a peer-reviewed scientific journal? --Uncle Ed 11:37, 14 March 2007 (UTC)

Having this as the only estimate within the GCM section is unbalanced. I don't understand your comment about J Clim - are you suggesting that everything within a sci journal is representative of the overall view? William M. Connolley 11:54, 14 March 2007 (UTC)

It sounds like you're saying that we should give our readers an understand of the overall view, rather than suggesting that new ideas challenging the mainstream "are" mainstream. Am I getting you correctly? --Uncle Ed 11:58, 14 March 2007 (UTC)

I'm suggesting the balance should be correct. The article is more accurate though less complete with this removed William M. Connolley 12:13, 14 March 2007 (UTC)
OK, so I've just rm'd the models section (it was essentailly null) and put Stotts numbers back in wher Stott was William M. Connolley 20:19, 15 March 2007 (UTC)

[edit] Satellite records

The page currently doesn't discuss that the satellite record is patched together from different satallites and there is no overall agreement on how to do this William M. Connolley 20:11, 15 March 2007 (UTC)

[edit] Graph removal

I have removed Image:Solar_variation_and_global_warming.gif since it misinterprets, and consequently misrepresents, the data. The data presented as "Solar Data" in the graph is a solar proxy in the form of 14C. More importantly the timescale used for "Solar Data" is the time-scale of 14C which lags 60 behind changes in solar activity (that is, if solar activity increases in 1900, we can expect to see corresponding changes in 14C around 1960), thus misrepresenting solar activity changes as occuring 60 years later than they actually do. Furthermore, by using proxy data rather than actual raw solar data (e.g sunspot number, for which there are very detailed records this century) more errors are introduced: 14C records are unreliable after 1950 due to nuclear testing, and post-1950 provide a poor proxy for solar data (which means solar data from 1890 onward is no longer well recorded in 14C). -- Leland McInnes 16:10, 26 March 2007 (UTC)

[edit] New Article: Cosmic Rays and Global Warming

Cosmic Rays and Global Warming

It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause. Comments: Submitted to ICRC 2007

Count Iblis 00:56, 29 June 2007 (UTC)

[edit] Statements of fact vs. opinion

There are a number of definite statements in this article which refer to controversial studies or simply studies that are preliminary, giving a misleading impression of the uncertainty surrounding many aspects of the science. It would good to start going through the items and putting in better qualifiers, but since this can sometimes be seen as partisan, would it be better to test the changes here first? 69.200.236.114 14:33, 8 July 2007 (UTC)

[edit] Neptune/Mars measurements?

Is it true what this article says, that Neptune and Mars are also warming up? This article is being linked to on the Neptune article so it shouldn't be misleading, and if it is then it should be removed. --Nathanael Bar-Aur L. 22:04, 2 December 2007 (UTC)

WCR is definitely an unreliable source. I've removed that link from the Neptune article (as far as I can see it wasn't discussed in the text). As far as can be told, Mars isn't warming up, but info is sparse. See Climate of Mars#Evidence for recent local climatic change and the extensive acrimonious discussion there. For my own view of the H+L paper, see [13] William M. Connolley 22:17, 2 December 2007 (UTC)
Fascinating. Thank you very much :-) --Nathanael Bar-Aur L. 22:40, 2 December 2007 (UTC)

[edit] Satellites

Are satellites or space probes ever used to study solar variation? The article doesn't seem to mention any.... (sdsds - talk) 04:10, 28 February 2008 (UTC)

Indeed they are. Per reference #3 in this article there is satellite data going back to 1978 - nearly three complete 11-year cycles. The use of satellites to study solar energy flux is also mentioned here. Hertz1888 (talk) 04:41, 28 February 2008 (UTC)

[edit] Merge?

Set up merge. Reason: Effect of sun angle on climate is basically a few illustrations and their explanations, which just as well can be used to make a few points of Solar variation more easy to grasp. Dysmorodrepanis (talk) 01:58, 19 March 2008 (UTC)

I've reverted. Your proposal to merge effect of sun angle on climate into solar variation makes me wonder if you have any idea what either of those two articles is about. Solar variation is about variations in energy that the sun emits. It has nothing to do with seasons on EARTH, or anything about the earth at all. If the earth disappeared, the topic of solar variation would still exist. Effect of sun angle on climate is about the way in which variations of the EARTH's position affect its absorption of energy from the sun. If there were no variations at all in energy emitted by the sun, the topic of effect of sun angle on climate would still be there. Michael Hardy (talk) 03:06, 19 March 2008 (UTC)
...I notice that there are some mentions of the effects on the earth in this article. But those are about the effect of solar variation on earth. The other article, effect of sun angle on climate, does not mention nor even hint at solar variation. It's about variations in geographic location on earth and variations in the earth's position, NOT about variations in the sun's output, which is the topic of this article. Michael Hardy (talk) 03:09, 19 March 2008 (UTC)

[edit] Wikiproject Earth

Hello i have recently proposed the Wikiproject Earth. This Wikiproject`s scope includes this article. This wikiproject will overview the continents, oceans, atsmophere and global warming Please Voice your opinion by clicking anywhere on this comment except for my name. --IwilledituTalk :)Contributions —Preceding comment was added at 15:36, 30 March 2008 (UTC)

[edit] New Research

According to the BBC there's been new research debunking the alleged link between global warming and sun activity. Here's the link to the story: http://news.bbc.co.uk/1/hi/sci/tech/7327393.stm Looks interesting. Darkmind1970 (talk) 10:12, 3 April 2008 (UTC)

The preprint of this now published article can be found here Count Iblis (talk) 13:42, 3 April 2008 (UTC)
Hmmm....that statement might be a little strong. They have shown a lack of correlation between cosmic ray intensity and cloud cover -- thus the hypothesis that solar activity might effect cosmic radiation intensity on earth, leading to variations in cloudiness and thus warming -- I think that hypothesis is kaput. But that is not the same as debunking a relationship between global warming (and cooling) and solar activity. For example see DYNAMICS OF CLIMATIC AND GEOPHYSICAL INDICES and look at the graphics. SunSw0rd (talk) 21:01, 15 April 2008 (UTC)

[edit] Time scale on graph

Just throwing this out there, what about a longer time scale graph for the page? If people want to draw conclusions about climate why not give them a thousand year graph or something so they can match it up themselves to the temperature record? —Preceding unsigned comment added by 67.164.67.33 (talk) 20:50, 18 May 2008 (UTC)