Jiang et al: Solar forcing of Holocene summer sea-surface temperatures in the northern North Atlantic

Posted: February 24, 2015 by tallbloke in solar system dynamics
Tags: ,

H/T to Chaeremon for flagging up this recent paper from Jiang et al which gets better detail on solar forcing of climate. Paywalled, abstract only, but there is a fugure from Jiang’s earlier 2005 paper covering 1200 years around Iceland.

jiang2005Abstract

Mounting evidence from proxy records suggests that variations in solar activity have played a significant role in triggering past climate changes. However, the mechanisms for sun-climate links remain a topic of debate. Here we present a high-resolution summer sea-surface temperature (SST) record covering the past 9300 yr from a site located at the present-day boundary between polar and Atlantic surface-water masses. The record is age constrained via the identification of 15 independently dated tephra markers from terrestrial archives, circumventing marine reservoir age variability problems. Our results indicate a close link between solar activity and SSTs in the northern North Atlantic during the past 4000 yr; they suggest that the climate system in this area is more susceptible to the influence of solar variations during cool periods with less vigorous ocean circulation. Furthermore, the high-resolution SST record indicates that climate in the North Atlantic regions follows solar activity variations on multidecadal to centennial time scales.

  • Received 21 October 2014.
  • Revision received 9 December 2014.
  • Accepted 10 December 2014.
  1. Hui Jiang1,
  2. Raimund Muscheler2,
  3. Svante Björck2,
  4. Marit-Solveig Seidenkrantz3,
  5. Jesper Olsen4,
  6. Longbin Sha1,3,
  7. Jesper Sjolte2,
  8. Jón Eiríksson5,
  9. Lihua Ran6,
  10. Karen-Luise Knudsen3 and
  11. Mads F. Knudsen3

+Author Affiliations


  1. 1Key Laboratory of Geographic Information Science and State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 200062 Shanghai, People’s Republic of China

  2. 2Department of Geology, Quaternary Sciences, Lund University, Sölvegatan 12, 22362 Lund, Sweden

  3. 3Centre for Past Climate Studies and Arctic Research Centre, Department of Geoscience, Aarhus University, DK-8000 Aarhus C, Denmark

  4. 4Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark

  5. 5Institute of Earth Science, University of Iceland, Askja, IS-101-Reykjavík, Iceland

  6. 6Second Institute of Oceanography, State Oceanic Administration, 310012 Hangzhou, People’s Republic of China
Comments
  1. Jaime says:

    I’ve noticed the Chinese seem to be doing a lot of research on solar forcing of North Atlantic SSTs, North Atlantic cool periods etc. They’re very bright people.

  2. DB says:

    Steve McIntyre at Climate Audit discussed this paper a bit last month vis a vis the Marcott paper.
    http://climateaudit.org/2015/01/08/ground-truthing-marcott/

  3. linneamogren says:

    Remember, we are not getting the correct TSI data from NASA’s satellite which sits 90,000 kilometers below the Earths atmosphere. So, how much more are we missing. When you look at sunspot and temperature data over several decades seems clear there is some influence. But maybe much more than we know due to NASA’s position.

    https://tallbloke.wordpress.com/2012/11/22/tim-cullen-the-problem-with-tsi-total-solar-irradiance/

  4. oldbrew says:

    Going back 9300 years means obliquity is a factor. Does that count as ‘solar activity’?

  5. old brew in your diagram what are the red arrows?

    Obviously solar has to be THE factor in determination of sea surface temperatures since visible light and UV light near the visible light wavelength penetrate the ocean surface waters to much greater depths then all other light such as IR.

  6. gymnosperm says:

    Obliquity would be included in both June and total “forcing” at 67 North. It’s not like they are relying in measurements of insolation. Like all other suggested orbital relationships, this 2005 figure shows a very unsatisfying correlation.

  7. tallbloke says:

    I would expect SST’s around Iceland to be strongly affected by volcanism. Pity we can’t see the new paper.

  8. It shows obliquity is less today (2000 AD) then it was around 8000 BC , more favorable for glaciation ,as well as Precession being much more favorable for glaciation as shown in the previous diagram Oldbrew, had sent.

    That diagram showing at the time of 8000 BC , N.H. experienced Perihelion during the summer less favorable for glaciation in contrast to today when the N.H. experiences Aphelion during the summer.

    Based solely on Milankovitch Cycles the earth is much more favorable today for glaciation as opposed to 8000 BC.

    Orbit eccentricity if taken into account being more or less neutral during that time span 8000 BC- 2000 AD.

    What is interesting is from the Holocene Optimum through today each warm period, those being the Minoan, Roman, Medieval, and the Modern Warm Period just recently, has tended to be cooler then the one previous to the most recent one.

    I think the slow moving cycles such as Land /Ocean Arrangements, Milankovitch Cycles , to name two are in a gradual cooling trend with solar variability being superimposed upon this gradual cooling cycle.

    Future, random events( terrestrial/extra terrestrial ) must always be taken into some consideration which would be SUPER superimposed upon the climate cycle if that should ever happen.

  9. Rog, I got it to work trial and error. See graph of obliquity . That is what I wanted to send the first time.

  10. Old Brew, the answer to your question is yes obliquity is a factor and I do count it as one of the variables of solar influences if not activity per say. My two cents worth.

  11. Doug Proctor says:

    Oldbrew: currently perihelion occurs during the Antarctic winter. The 6.5% increase in insolation is 87 W/m2 (Relative to the peak of the Arctic summer). Yet the Southern Hemisphere has an annual temperature 2C lower than the Northern. The extra heat is being overwhelmed by other forces or factors. Reverse that – perihelion during the Arctic summer – and you sure should see a difference. Warmer Northern and colder Southern.

    The last Arctic summer perihelion occurred during the Minoan warm age by your diagram. Probably not a coincidence.

  12. The Minoan period occurred only around 3500 years ago well after the time perihelion occurred during the Arctic summer some 10000 years ago or 8000 BC.

    Which is what the diagram shows from old brew.

  13. Excellent info. you posted from Steve McIntyre.

    It shows the long term trend in temperature for the past 10000 years is down punctuated by warm periods.

  14. There is no Holocene Temperature Conundrum which comes about due to the absurd climatic models(going against the accurate data ,diatom/alkenone data ,which shows a cooling through out the Holocene which is correct and to be expected – Slow Moving Milankovitch Cycles ) which are 100% incapable of forecasting the climate correctly.

    The faith that has been put in these models at this late date mystifies me because they have been shown to be so far off in every single facet of the climate they have predicted.

    Yet an article such as the one by Liu et al, still comes out giving credence to these worthless climate models.

    I have news, the ending of this scam along with the useless climate models is right around the corner which will be due to natural climate variability.

  15. From Richard Telford Article

    To summarise, changes in ice-sheet albedo, meltwater flux and greenhouse gases will all have acted to make the late Holocene warm relative to the early Holocene. Set against this is the orbital forcing that should give high-latitude warm summers in the early Holocene, but no annual forcing

    My reply – the changes in ice sheet albedo were not in play after 8000 BC. Greenhouse gases are a response to the climate not a cause for the climate. Melt water flux would have been taken out of the equation around 8000 BC due to ice-sheet retreat.

    So all of the agents he says should make the Late Holocene warmer are no longer in the equation from the Holocene Optimum -Present.

    What is left is Milankovitch Cycles pointing to a cooler trend with solar variability(primary and secondary effects ) superimposed upon that trend.

    This seems to be holding up from the Holocene Optimum to Present, when one evaluates the Holocene Optimum relative warmth to the warmth of the Minoan, Roman ,Medieval ,and Modern Warm periods each less warm then the previous period along with the cold periods ending with thus far the most recent coldest period of all The Little Ice Age , since the Holocene Optimum.

  16. The chart for sunspots only extends to year 1900 AD on the left side. The chart also clearly shows an overall decrease in solar activity through out the Holocene until the modern maximum of solar activity which started around 1920 ,which is not shown on this chart.

    From what I can see Milankovitch Cycles are trending toward a colder climate for the globe from the Holocene Optimum -Present , while solar activity variability superimposed upon the Milankovitch Cycles, is showing an overall slight down trend in activity from the Holocene Optimum -Present despite some strong periods within the trend such as the Medieval period or the 1920-2000 period of time.

    The recent strong periods of solar activity according to this chart in the above appearing to be shorter in duration in contrast to what they were 8000 to 10,000 years ago or 6000 BC to 8000 BC.

  17. One other point is the SH. and N.H. are not created equally when it comes to their response to Milankovitch Cycles.

    The S.H. is set up as such , that it does not really matter if summer time insolation increases or decreases because the area of land that is entrenched in snow/ice is going to remain the same regardless of summer time insolation changes , in contrast to the N.H. where a difference in summer time insolation can cause a significant difference in the land area covered by snow/ice, thus effecting the albedo of the entire planet.

    S.H. albedo remaining steady while N.H. albedo increasing due to favorable Milankovich Cycles.

  18. I should have said in my 11:25 pm post

    the changes in ice sheet albedo were not in play after 6000 BC or 8000 years ago.

    8000 BC should be 6000 BC where it should appear.

  19. Bob Weber says:

    Interesting how solar activity was so much higher during the high points of Egyptian civilization.

    “…they suggest that the climate system in this area is more susceptible to the influence of solar variations during cool periods with less vigorous ocean circulation.”

    My analysis of SSTs indicates that solar spikes during low solar activity periods in the modern era, when temps are at a minimum, also lead to rapid warming spikes in SSTs. Too many wiggles match between solar and SSTs for it to be a coincidence.

    “Furthermore, the high-resolution SST record indicates that climate in the North Atlantic regions follows solar activity variations on multidecadal to centennial time scales.”

    Other parts of the ocean also follow solar variations closely in time, from what I’ve seen.

    From Salvatore: “Obviously solar has to be THE factor in determination of sea surface temperatures since visible light and UV light near the visible light wavelength penetrate the ocean surface waters to much greater depths then all other light such as IR.”

    Indeed.

    Discussed here https://tallbloke.wordpress.com/2013/10/23/new-paper-finds-solar-uv-varies-up-to-100-percent-during-solar-cycles-confirms-solar-amplification-mechanism/

    and here

    http://wattsupwiththat.com/2013/10/28/solar-spectral-irradiance-uv-and-declining-solar-activity/

  20. oldbrew says:

    SdP says: ‘oldbrew in your diagram what are the red arrows?’

    The orientation moves through 90 degrees each time, with the seasons. The position of the arrows shows the amount of tilt.

    SdP: ‘Based solely on Milankovitch Cycles the earth is much more favorable today for glaciation as opposed to 8000 BC’
    Bob Weber: ‘Interesting how solar activity was so much higher during the high points of Egyptian civilization’

    Are these two comments saying in effect the same thing?

  21. Bob Weber says:

    I don’t know oldbrew, I wasn’t my intent.

    What is interesting is the many instances of peoples living underground long ago for long periods in either natural or man-made structures, a practice that was not continued indefinitely. Perhaps people then were seriously affected by intense solar radiation and geomagnetic storms, and sought relief underground. Or maybe it was the cold they were escaping from under low solar conditions.

    I subscribe to the idea that solar activity was much higher in the past at times, like the chart says that Salvatore showed above. If he could post a link to the source of that plot, we could learn more about how it was determined, such as where the proxy data was investigated, which may not have much to do with the area of interest of Jiang’s paper.

    That plot was made with some proxy for SSN, as no one was counting spots 10,000 years ago (that I know of), and it seems unlikely to me that whatever the proxy was could possibly vary so much so often under solely Milankovitch Cycles (w/ obliquity) as those change smoothly over longer timespans than the solar activity changes shown in Salvatore’s graphic. The downward trend in the SSN proxy however could be a sign of the obliquity influence.

    I really only focus on post-1750, probably at my disadvantage. This article is based on SSTs and solar, which sparked my interest, as that’s what I use, and post-1750, direct observations and measurements are available instead of needing proxies.

    “position of the [red] arrows shows the amount of tilt.” I guess I’m a having a hard time seeing the “amount” of tilt in the red arrows. Are you sure it isn’t the direction of tilt at the perihelion, aphelion, equinox, and solstice? It’s not clear.

    Here’s something I just looked at from http://en.wikipedia.org/wiki/Milankovitch_cycles

    Link

    The solar insolation at 65 degrees north tracks with obliquity. It appears there was indeed a spike in both about 10kyr ago, like Salvatore’s SSN (proxy) graphic shows, followed by a downward trend to year “0”.

    Quoting from the wiki article

    “The amount of solar radiation (insolation) in the Northern Hemisphere at 65° N seems to be related to occurrence of an ice age. Astronomical calculations show that 65° N summer insolation should increase gradually over the next 25,000 years.[22] A regime of eccentricity lower than the current value will last for about the next 100,000 years. Changes in northern hemisphere summer insolation will be dominated by changes in obliquity ε. No declines in 65° N summer insolation, sufficient to cause a glacial period, are expected in the next 50,000 years.

    An often-cited 1980 study by Imbrie and Imbrie determined that, “Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend that began some 6,000 years ago will continue for the next 23,000 years.”[23]

    More recent work by Berger and Loutre suggests that the current warm climate may last another 50,000 years.”[24]

    [24] Berger and Loutre here- http://www.clim-past-discuss.net/2/519/2006/cpd-2-519-2006.pdf

    I haven’t read any of that and probably won’t – too busy focusing on post-1750. Interesting though.

  22. Good discussion. Thanks Oldbrew for your explanation of the red arrows.

    To answer your question oldbrew I think we have very slow moving Milankovitch Cycles which have been trending the climate cooler since the Holocene Optimum ,and superimposed on that trend is solar variability which for the most part has also trended down since the Holocene Optimum but with spikes of active periods especially the most recent one from1920-2000,which have caused counter trends in the overall cooling trend when the spikes of solar activity occur.

    Bob do you agree with this explanation ?

  23. Bob Weber says:

    Yes I do. Good point.

  24. Bob Weber says:

    I use several lines of evidence to show the modern maximum in solar activity was from 1936-2003, to be discussed at a later date. You should definitely go to 2003, the SC23 max end year, and while 1920-1935 don’t look “bad”, the SSNs then weren’t higher than previous cycle high points, and didn’t go above those other high points until 1936. I’d like to discuss this more down the road….

  25. tallbloke says:

    Bob: I’ve uploaded the image to the talkshop server. That chart is the reason I think we may get away with not decending into a glacial period this time. Thank goodness for global warming and Milankovitch.🙂

    I agree with your 1936-2003 period. That period coincides with the rise period I found when I integrated the sunspot number departing from the long term average (which is also the ocean equilibrium value).

  26. Rog, but Milankovitch cycles are favoring further cooling going forward.

  27. Bob Weber says:

    Thank you Tallbloke. I think it’s important we’re all on the same page, literally, and figuratively.

  28. dscott says:

    Tallbloke, I believe you have misinterpreted Salvatore’s chart on obliquity. The top end of the chart is 22 degrees, the bottom end of the chart is 27 degrees. We are heading towards the minimum. That full cycle lasts 41kyrs from minimum to minimum.

    Every Ice Age without exception in the last one million years of records begins when the obliquity falls below 23.5 degrees as we have done (23.42 degrees). NO EXCEPTIONS! There are no warm periods that last 40kyrs, none!

    Ice Ages last, 80kyr to 120kyr because when obliquity achieves the greatest value of 24 degrees at 41kyr intervals, the maximum warming angle, however, not all Ice Ages end on that maximum, sometimes there is not enough melting momentum to change the climate trend. This is why we have an average of 100k yrs. Notice the mode of Ice Age lengths 80kyr, 120kyr, there are no 40kyr lengths.

  29. dscott the chart is on correct , it just happens to show lower values for obliquity at the top of the chart, rather then the bottom of the chart.

  30. Deglaciation occurs when the earth’s orbit is at maximum eccentricity.

    My question is does this deglaciation take place when the maximum eccentricity of earth’s orbit occurs while the N.H. experiences perihelion during the summer ?

  31. Rog., my commentary under the topic -global warming slowdown probably due to natural cycle is not posting. Thanks.

  32. As far as the circular orbit equating to less solar insolation perhaps over the entire earth but not in the N.H. high latitudes when aphelion occurs during the N.H. summer when the orbit of the earth attains maximum eccentricity. Do you agree?

    Rog, for the article that was run some 4 years ago on Milankovitch Cycles.

  33. Svan says:

    Dscott, thank you for posting this: “Every Ice Age without exception in the last one million years of records begins when the obliquity falls below 23.5 degrees as we have done (23.42 degrees). NO EXCEPTIONS! There are no warm periods that last 40kyrs, none!”

    Yes, that short Berger and Loutre paper about the current interglacial period possibly lasting 40,000 years has no substance at all. Maybe a nod to the warmist propaganda to continue getting funding?

    While your first statement is quite true, this might help convey the idea further: The periods of glaciation during the last million years each began after each peak in eccentricity, and specifically when the declining obliquity cycle at that time fell below 23.5 degrees.

    It is both eccentricity and obliquity in combination that drive the temperature cycle, as I’m sure you know. Neither one alone suffices. The apparent anomalies in the temperature-to-eccentricity match are fully reconciled by including obliquity, for the full 1 m years. The prior 1.5 m years of the present ice age matches obliquity alone.

    I have a graph showing temperature, obliquity, and eccentricity for the past 800 kyr that shows this very clearly, but no idea how to upload it here.

  34. Svan says:

    Salvatore, that’s an interesting question: “does this deglaciation take place when the maximum eccentricity of earth’s orbit occurs while the N.H. experiences perihelion during the summer?”

    The history shows that eccentricity + perihelion is not the driver, eccentricity + obliquity is the driver. If obliquity peaks while eccentricity is not at least halfway near peak it will have little or no effect.

    However, perihelion surely has some effect. Perhaps it acts as a smaller trigger within the longer obliquity cycle? The same could be true of the decline into a glacial period. I’d love to see a graph with it included.

  35. Svan says:

    I would like to see knowledgeable folks (such as those who post here) use the more correct phrases of “glacial period” or “period of glaciation” rather than “ice age”. We are in an ice age right now, and the omission of that fact by the msm is surely intentional. The present ice age, by one definition, has been going on for the past 2.5 m years (the Pleistocene Ice Age), and by another definition has been going on for about 13 m years (as defined more accurately by a period during which there is a permanent ice cap at either pole). In any case, ice ages happen every 150 million years, and last for tens of millions of years. This one is not going away any time soon.

    The present ice age, for the past 1 m years, is characterized by repeating alternating cycles of (approximately) 85,000-90,000 years of relative cold, called glacial periods, and (approximately) 10,000-15,000 years of relative warm, called interglacial periods. The temperature differential from peak to trough can be as much as 15 degrees C. We’re in a nice, warm, “peak” that has lasted for about 12,000 years, and will be returning soon to more typical temperatures. (I know everyone here knows this, I’m just spelling it out for the sake of clarity on the terms.)

    It should be noted that even the warmest of the interglacial periods for the past million years are much colder than the average global temperatures prior to the ice age we are in. The earth has been in a cooling cycle for at least 50 million years.

    Just trying to be helpful.🙂