New paper speculates on volcanoes during the Little Ice Age

From NCAR/UCAR, they’re still trying to stamp out solar influence as a potential cause of the Little Ice Age. One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism? We may get the answer to this question in the coming years as the Ap solar-geomagnetic activity index is at an all-time low in the records.

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Study may answer longstanding questions about Little Ice Age

January 30, 2012

BOULDER — A new international study may answer contentious questions about the onset and persistence of Earth’s Little Ice Age, a period of widespread cooling that lasted for hundreds of years until the late 19th century.

gifford miller

Gifford Miller collects vegetation samples on Baffin Island. (Photo courtesy University of Colorado Boulder.)

The study, led by the University of Colorado Boulder with co-authors at the National Center for Atmospheric Research (NCAR) and other organizations, suggests that an unusual, 50-year-long episode of four massive tropical volcanic eruptions triggered the Little Ice Age between 1275 and 1300 A.D. The persistence of cold summers following the eruptions is best explained by a subsequent expansion of sea ice and a related weakening of Atlantic currents, according to computer simulations conducted for the study.

The study, which used analyses of patterns of dead vegetation, ice and sediment core data, and powerful computer climate models, provides new evidence in a longstanding scientific debate over the onset of the Little Ice Age. Scientists have theorized that the Little Ice Age was caused by decreased summer solar radiation, erupting volcanoes that cooled the planet by ejecting sulfates and other aerosol particles that reflected sunlight back into space, or a combination of the two.

“This is the first time anyone has clearly identified the specific onset of the cold times marking the start of the Little Ice Age,” says lead author Gifford Miller of the University of Colorado Boulder. “We also have provided an understandable climate feedback system that explains how this cold period could be sustained for a long period of time. If the climate system is hit again and again by cold conditions over a relatively short period—in this case, from volcanic eruptions—there appears to be a cumulative cooling effect.”

“Our simulations showed that the volcanic eruptions may have had a profound cooling effect,” says NCAR scientist Bette Otto-Bliesner, a co-author of the study. “The eruptions could have triggered a chain reaction, affecting sea ice and ocean currents in a way that lowered temperatures for centuries.”

The study appears this week in Geophysical Research Letters. The research team includes co-authors from the University of Iceland, the University of California Irvine, and the University of Edinburgh in Scotland. The study was funded in part by the National Science Foundation, NCAR’s sponsor, and the Icelandic Science Foundation.

Far-flung regions of ice

Scientific estimates regarding the onset of the Little Ice Age range from the 13th century to the 16th century, but there is little consensus, Miller says. Although the cooling temperatures may have affected places as far away as South America and China, they were particularly evident in northern Europe. Advancing glaciers in mountain valleys destroyed towns, and paintings from the period depict people ice-skating on the Thames River in London and canals in the Netherlands, places that were ice-free before and after the Little Ice Age.

“The dominant way scientists have defined the Little Ice Age is by the expansion of big valley glaciers in the Alps and in Norway,” says Miller, a fellow at CU’s Institute of Arctic and Alpine Research. “But the time in which European glaciers advanced far enough to demolish villages would have been long after the onset of the cold period.”

Miller and his colleagues radiocarbon-dated roughly 150 samples of dead plant material with roots intact, collected from beneath receding margins of ice caps on Baffin Island in the Canadian Arctic. They found a large cluster of “kill dates” between 1275 and 1300 A.D., indicating the plants had been frozen and engulfed by ice during a relatively sudden event.

The team saw a second spike in plant kill dates at about 1450 A.D., indicating the quick onset of a second major cooling event.

To broaden the study, the researchers analyzed sediment cores from a glacial lake linked to the 367-square-mile Langjökull ice cap in the central highlands of Iceland that reaches nearly a mile high. The annual layers in the cores—which can be reliably dated by using tephra deposits from known historic volcanic eruptions on Iceland going back more than 1,000 years—suddenly became thicker in the late 13th century and again in the 15th century due to increased erosion caused by the expansion of the ice cap as the climate cooled.

“That showed us the signal we got from Baffin Island was not just a local signal, it was a North Atlantic signal,” Miller says. “This gave us a great deal more confidence that there was a major perturbation to the Northern Hemisphere climate near the end of the 13th century.”

The team used the Community Climate System Model, which was developed by scientists at NCAR and the Department of Energy with colleagues at other organizations, to test the effects of volcanic cooling on Arctic sea ice extent and mass. The model, which simulated various sea ice conditions from about 1150 to 1700 A.D., showed several large, closely spaced eruptions could have cooled the Northern Hemisphere enough to trigger the expansion of Arctic sea ice.

The model showed that sustained cooling from volcanoes would have sent some of the expanding Arctic sea ice down along the eastern coast of Greenland until it eventually melted in the North Atlantic. Since sea ice contains almost no salt, when it melted the surface water became less dense, preventing it from mixing with deeper North Atlantic water. This weakened heat transport back to the Arctic and created a self-sustaining feedback on the sea ice long after the effects of the volcanic aerosols subsided, according to the simulations.

The researchers set solar radiation at a constant level in the climate models. The simulations indicated that the Little Ice Age likely would have occurred without decreased summer solar radiation at the time, Miller says.

About the article

Title: Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks

Authors: Gifford Miller, Áslaug Geirsdóttir, Yafang Zhong, Darren J. Larsen, Bette L. Otto-Bliesner, Marika M. Holland, David A. Bailey, Kurt A. Refsnider, Scott J. Lehman, John R. Southon, Chance Anderson, Helgi Bjornsson, Thorvaldur Thordarson,

Publication: Geophysical Research Letters

=============================================================

Here’s the paper abstract, the actual paper is not yet available (another science by press release that we can’t check).

http://www.agu.org/pubs/crossref/pip/2011GL050168.shtml

GEOPHYSICAL RESEARCH LETTERS, doi:10.1029/2011GL050168

Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks

Key Points

  • Little Ice Age began abruptly in two steps
  • Decadally paced explosive volcanism can explain the onset
  • A sea-ice/ocean feedback can sustain the abrupt cooling

Authors:

Gifford H Miller

Aslaug Geirsdottir

Yafang Zhong

Darren J Larsen

Bette L Otto-Bliesner

Marika M Holland

David Anthony Bailey

Kurt A. Refsnider

Scott J. Lehman

John R. Southon

Chance Anderson

Helgi Björnsson

Thorvaldur Thordarson

Northern Hemisphere summer temperatures over the past 8000 years have been paced by the slow decrease in summer insolation resulting from the precession of the equinoxes. However, the causes of superposed century-scale cold summer anomalies, of which the Little Ice Age (LIA) is the most extreme, remain debated, largely because the natural forcings are either weak or, in the case of volcanism, short lived. Here we present precisely dated records of ice-cap growth from Arctic Canada and Iceland showing that LIA summer cold and ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430-1455 AD. Intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past millennium. A transient climate model simulation shows that explosive volcanism produces abrupt summer cooling at these times, and that cold summers can be maintained by sea-ice/ocean feedbacks long after volcanic aerosols are removed. Our results suggest that the onset of the LIA can be linked to an unusual 50-year-long episode with four large sulfur-rich explosive eruptions, each with global sulfate loading >60 Tg. The persistence of cold summers is best explained by consequent sea-ice/ocean feedbacks during a hemispheric summer insolation minimum; large changes in solar irradiance are not required.

Received 29 November 2011; accepted 30 December 2011.

Citation: Miller, G. H., et al. (2012), Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks, Geophys. Res. Lett., doi:10.1029/2011GL050168, in press.

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287 thoughts on “New paper speculates on volcanoes during the Little Ice Age

  1. I have read a book near 40 years ago about the influence of the solar cycle and earth’s climate. That included a link between the solar cycle and the number of earthquackes and volcanic eruptions, which seem to cluster in the rising edge of the solar cycle. I haven’t done the math, but it is worth to see if there is some correlation and a possible link via the earth’s and sun’s magnetic field interactions and continental shelves floating atop of a magnetic earth kernel…

  2. One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism?

    An interesting question. From an energy point of view, it doesn’t seem likely — I’ve estimated the power associated with magnetic induction and although it is a very large number, it is a very small number compared to the size the Earth. Of course, I could have made a mistake in my arithmetic, but I wouldn’t think that the forces are large compared to, say, tidal forces.

    rgb

  3. Even if there is no Solar influence, this is a sort of scientific game over!

    If the LIA was caused by volcanoes, that’s an admission that it was warmer before and since the LIA, we’ve had a relatively quiet period as regards volcanoes.

    Who needs CO2 if it’s reduced volcanic activity that caused the warming?

    DaveE.

  4. “One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism?”

    I’ve wondered the same thing but have never voiced the question to anyone. On the surface it seems implausible, but stranger things have been correlated before. GCRs inducing cloud formation, anyone???

  5. Don’t you get a little giddy when you read the words “powerful computer climate models”? I know I sure do! I wonder if they discuss amongst themselves how much RAM is necessary to show the true beauty that can only be CO2? Bawhahaha!

  6. I thought the Little Ice Age either did not not exist or was localized to northern Europe. Just ask Michael Mann and his famous Hockey Stick (a study of tree rings in one very very small region of Northwest Siberia). His trees didn’t find this cooling.

  7. They assert:

    Intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past millennium.

    but do not provide supporting details. Have these two periods been recognized as having significantly greater volcanic eruptions than any other comparable periods?

    Let me guess: models all the way down?

  8. In the Clube and Napier astronomical theory (1980s and 1990s) the Little Ice Age had an association with increased meteoric activity as that was hypothesized to cause large amounts of dust in the upper atmosphere and create an opaque sky – virtually the same kind of thing as suggested by increased volcanic activity. In the same theory meteoric activity was responsible for the downturn in climate in the Late Roman period, 4th, 5th and 6th centuries ad roughly, and the 9th century ad short spell cold/wet weather episodes (coinciding with the Vikings, spurred on by an excited sky) and so back into history. This sort of thing became lost in the hypothetical 1500 year Bond cycle that never quite seems to fit into a 1500 year series. Clube and Napier were popular for awhile and wrote a couple of books and countless articles that all just kind of disappeared. They were never on the radar in the US.

  9. This just goes to show that generally climatologists just don’t know enough even to start to pronounce on what drives climate change, even with all their “most powerful computer programmes”.

  10. Wasn’t Gifford Miller in that Ice Age “documentary” with Mr Spock in the 1970s warning of the impending march of the ice sheets

  11. I think I can explain the MWP with this theory too. Inverse volcanoes. They sucked aerosols in rather than emitting them for the LIA.

    Thus, the global temperature prior to the carbon era was flat, and the handle of the hockey stick was crooked no more.

  12. Some ‘alarmist’ bells started ringing when I read “there appears to be a cumulative cooling effect”.
    All that needs is a reference to the Truth…

  13. This paper would somewhat confirm what Dr. Svalgaard has found. TSI, even during minimums, is bascially flat. This also demonstrates that the earth recovers from a long period of cooling. It took centuries, after it was so cold, to warm to equalibrium again.
    For our clmate to work effectively, it requires the Arctic to be virtually ice free in the summers.
    It is well documented that the Arctic warmed enough approx 6,000YBP to be ice free in the summer. This lasted for approx 3500 years, and then it cooled, prob from volcanic erruptions.

    The resolution of past temp proxies is not good enough to rule out that we may be as warm as the MWP now. The current period of warmth is well within the error bounds of the proxy reconstructions.

    The good thing in all of this is…..we seem to be finally getting back to what would be considered a “average” temperature of the Holocene.

  14. Are these the eruptions being referenced?

    Billy Mitchell Bougainville & Solomon Is. 6 1580
    Bardarbunga Iceland 6 1477
    1452-53 ice core event New Hebrides Arc 6 1452-53
    Quilotoa Andes, Northern Volcanic Zone 6 1280

  15. Amazing what inconsistencies these guys shoulder just to avoid the solar influence.

    There is no little ice age in most Hockey Stick graphs

  16. I’m fine with the idea that increased Volcanism could have caused such events, but is there any direct physical evidence for these eruptions? It’s not clear from the press release.

  17. Since the little Ice Age interrupts the Medieval Warm Period, are we all clear now that the optimum temperature is a lot warmer?

  18. oldseadog says:
    January 30, 2012 at 12:28 pm
    This just goes to show that generally climatologists just don’t know enough even to start to pronounce on what drives climate change, even with all their “most powerful computer programmes”.

    Does anybody know why climate models show increased CO2 causes CAGW? Because that’s how the models were programmed!

    Climate models are computer programs and merely do what they are programmed to do. At best, computer models illustrate an hypothesis. The models work they way they do because that’s how the models believe the climate works.

  19. Skeptics have pointed out how the climate models originally used to promote global warming were designed — with no real evidence behind it — to be unstable to slight warming due to increases of atmospheric CO2 (water vapor was supposed to increase and amplify the CO2 warming). Now, to explain the LIA, they have set up a climate model that is unstable in the cold direction to several closely-spaced volcanic eruptions. The take away fact, then, is

    The greatly reduced numbers of sunspots during the LIA were just a coincidence. We can make our climate models unstable to slight cooling to show this must be so!

    This not really very persuasive.

  20. “Does a reduced solar-magnetic influence prompt more volcanism?”
    Anthony,
    I’m pretty sure I’ve heard Joe Bastardi opine that it does. It’s been a while, and perhaps I misinterpreted, but I do believe I’ve heard him say something to this effect.

  21. I find it hard to believe that this was the only active period for volcanoes during the Holocene. What happened during other active times? What, you forget to look?

    Also, we had a couple of fairly good sized volcanoes in the last 30 years. While they did drop temps for a year or so, the temps bounced back right away. Was this non-supportive evidence covered in the paper?

    Finally, I thought that less ice in the Arctic was supposed to slow the Gulf stream. Are they now saying it is more ice? The way things keep changing I need a program to keep up.

  22. I would like to see this team in the same room with “The Team” discussing little ice age. Mann has declared that there was none, and no MWP.

  23. Robert Brown says:
    January 30, 2012 at 12:04 pm
    From an energy point of view, it doesn’t seem likely

    Furthermore since the solar effect on the ionosphere ( and the lithosphere electrical induction) is strongest during solar max, it would follow that number of volcanic eruptions would correlate with the peaks rather then troughs of the sunspot cycle.
    There are some indications that solar storms may be loosely linked to the earthquake occurrence, currently there is a strongish geomagnetic disturbance is in the progress (Z vector about 0.5% of the Earths field intensity, really strong ones exceed 1% of the static GMF)

    http://flux.phys.uit.no/cgi-bin/plotgeodata.cgi?Last24&site=tro2a&

    Last march Japan’s M9 geomagnetic storm was approaching 1% for vertical component and about 10% for the horizontal component. H vector is considered to be occasional quake trigger in a fault which may entered the critical phase. Currently H component has changed by about 4%.
    For more details see:

    http://www.vukcevic.talktalk.net/gms.htm

    Each storm shifts Z vector one notch up in the Eastern magnetic Hemisphere (cantered on Siberia), and one notch down in the WH cantered on the Hudson Bay area, hence drift of the virtual magnetic pole is Russia bound.

    http://www.vukcevic.talktalk.net/Tromso.htm

    The most recent World Magnetic map is available here:

    http://www.ngdc.noaa.gov/geomag/data/mag_maps/pdf/F_map_mf_2010.pdf

    It is worth noting that the Siberian field has surpassed the Hudson Bay in mid 1990s, and currently is about 4% stronger (total field 61 against 59 microT).
    The bifurcation changes in the Earth’s Nth Hmsphr’s field (not present in the SH) strongly correlate with the Arctic temperature anomaly:

    http://www.vukcevic.talktalk.net/NFC1.htm

  24. Camburn says:
    January 30, 2012 at 12:39 pm

    “This paper would somewhat confirm what Dr. Svalgaard has found. TSI, even during minimums, is bascially flat. ”

    They did not make any studies of the sun. They set the irradiance to a constant in the model so the study confirms nothing regarding the sun. With that said I do not make any claims that it is not true that sun has very low variability in it’s irradiance.

  25. “powerful climate models”

    Accurate climate models would be even more impressive – and more useful.

  26. Why is it that small changes in albedo induces by aerosols, even though not man made, can cause rather dramatic changes in temperatures BUT any changes in output from a dynamic star cannot ??

    Surely their theory simply argues against their argument that solar forcings do not count as reflecteing energy back into space would have the same effect as reduced solar energy due to the Sun.

    Are they trying to claim they have absolute proof that the Sun’s input to Earth is actually a constant and never varies by an amount to affect Earth’s temperatures ??

    I’d like to see that data and how it was measured.

  27. The BBC’s take on this press release can be found at : –

    http://www.bbc.co.uk/news/science-environment-16797075

    Richard Black’s opening paragraph: –
    “The Little Ice Age was caused by the cooling effect of massive volcanic eruptions, and sustained by changes in Arctic ice cover, scientists conclude”
    No CO2 there, then.
    But – as AleaJactaEst has noted, there were models.
    And the f’our’ ‘tropical’ eruptions are as yet unidentified. Is that state of the art for medieval volcanoes?
    Interesting to see the BBC adding
    “Analysis of the later phase of the Little Ice Age also suggests that changes in the Sun’s output, particularly in the ultraviolet part of the spectrum, would also have contributed cooling.”

    And the link from the BBC’s “Analysis of the later phase” [emboldened in the original] –
    goes to http://www.bbc.co.uk/news/science-environment-15199065
    which starts: –
    “Recent cold winters that brought chaos to the UK and other places in northern Europe may have their roots in the Sun’s varying ultraviolet emissions”.

    Now, maybe the volcanoes did set off a Local [but why European, when the volcnoes, we are told, were tropical] cooling but to putatively dismiss solar radiation variance seems, to me, rather a lot to read into the models presented. Not necessariy wrong – but possibly more than the evidence presented – from models – can confirm.

    At least the plants were from the non-model universe.

  28. Are these the same guys who tried to tell us temperatures had been stable before the modern man induced warming – ie hockey stick ??

    If so how do they reconcile a Little Ice Age only a few hundred years ago ??

  29. One thing is for sure…. it is a great thing that CO2 emissions continued along the business as usual scenario and the alarmists weren’t successful in getting CO2 emissions since 2000 drastically reduced or they would be pointing to Hansen’s famous 1988 graph and claiming they were wildly successful, They would be crowing that the current downward temperature trend proves the models are accurate and that they had saved the world. We skeptics and the world would be royally screwed starting about now.

  30. … large changes in solar irradiance are not required.

    Am I missing something or is this a paper tiger. Who, exactly, postulated large changes in solar irradiance?

  31. “The study, which used analyses of patterns of dead vegetation, ice and sediment core data, and powerful computer climate models”

    Not just computer models but “powerful” computer models. And where and when were these volcanic eruptions? Evidence upon which they are based in this “study”? I suppose the model says they happened. There are a multitude of coulda, woulda, shoulda variables that could be introduced to explain the cooling that was, I note, previously denied by these folks.

  32. Miller and all don’t seem to list any particular volcanic eruptions (where? when? how big?) in this study. Call me naive, but I would think that the simulations on these “most powerful computer programs” would have to include some kind of such data.

    Pinatubo and El Chicon both produced cooling effects of >0.5C, but their effects didn’t last more than a couple of years. If these hypothesized serial volcanoes were to have had any “cumulative cooling effect”, they must have been geologically instantaneous/simultaneous

    Color me skeptical (as always)

    There’s just no money to be made off blaming the Sun

  33. The supposed Kuwae eruption fits the 1450+/- window and is speculated to be about 6X Mt Pinatubo in size, which suggests possible global cooling impact. This paper identifies an unknown eruption in the 1250-1260 time period in the Dome A core

    http://www.igsoc.org/journal/current/207/j11J138.pdf

    A detailed 2840 year record of explosive volcanism in a shallow ice
    core from Dome A, East Antarctica

  34. “…paintings from the period depict people ice-skating on the Thames River in London”

    More than just ice-skating. Paintings show they used to spit-roast whole pig/cow/deer on the ice.

  35. “The researchers set solar radiation at a constant level in the climate models”
    Then the models did not even have the correct input data. End of.

  36. “The researchers set solar radiation at a constant level in the climate models. The simulations indicated that the Little Ice Age likely would have occurred without decreased summer solar radiation at the time, Miller says.”

    No, what it says is the models are tuned to give the desired result regardless of changes in solar radiation.

  37. HI M.A.

    I agree with your post above. There has been a demonstrated correlation between the magnetic field strength etc for quite some time.

    Dr. Svalgaard is also showing that TSI is pretty flat over very long periods of time.

    I have never bought into the theory that TSI was the cause of the LIA, NOR the MWP. I had always looked at the MWP as a rebound period, just as the present period is. When one examines long term temps, and take the noise of weather out, it is readily apparant that a somewhat drastic stimuli quickly changes the climate.

    carol says:
    January 30, 2012 at 12:22 pm
    Concerning a Bong Type Event. There is more evidence being found now as the the cycle of a Bond Event. It is apparant in ice proxy data from the Arctic. Whether it is world wide is still somewhat in question, but that is mainly because so much of the Southern Hemisphere is water. Hard to get good proxy data there.

    I would not count it out at this time.

    Overall, I am just thankful that we are getting back to “normal” temperatures now.

  38. @M.A.Vukcevic says:
    January 30, 2012 at 1:06 pm
    Really important!, you are being a Galileo Galilei
    However: You are being, like him, blasphemous!. How do you dare to doubt of the holy dogmas of Climate Change Church and the sainthood of its most renowned bishops?
    Your publications will be included in the INDEX!!

  39. Jerker Andersson says:
    January 30, 2012 at 1:08 pm
    “They did not make any studies of the sun. They set the irradiance to a constant in the model so the study confirms nothing regarding the sun. With that said I do not make any claims that it is not true that sun has very low variability in it’s irradiance.

    I know they left the TSI flat. That was my point. With a flat TSI, they were able to replicate the temperature pattern based on the volcanoes at that time. By not trying to discount solar variation, they actually proved there is very little.

  40. I have a different question. The mechanism by which the solar cycle has influenced climate is hypothesised to be a change in the ionisation rate altering the density of cloud seeding particles in the upper atmosphere. What interests me is whether this mechanism is still going to function in an age of air travel and industrial particulate emissions. There are a lot of anthropogenic cloud seeds up there now that were not there is the past. I wonder to what extent this will interrupt the mechanism.

  41. The paper is another hit against the CAGW supporting science of the IPCC. Natural events, once again, can be used to support arguments that the climate for the last +1000 years has a natural variation. There is increased credence that the modern period has a natural climate variation; with the IPCC’s postulated anthropogenic influence to the contrary notwithstanding.

    John

  42. So if we cancel out the LIA cause by volcanoes, the current warming is just one long continuation of the Medieval Warming Period, Roman Warming Period, all the way back to …..

    Great! Big mystery solved, nothing to worry about, can I have my taxes back please?

  43. We may get the answer to this question in the coming years as the Ap solar-geomagnetic activity index is at an all-time low in the records.
    Ap is constructed from geomagnetic data. Such data is available back to the 1840s and Ap can be constructed from that data just as well as from the standard ~12 observatories used since 1932. Here is such a construction http://www.leif.org/research/Ap-1844-now.png The current low values are not exceptional. Similar levels were reached in 1901-1902 and 1878-1879. Since 1844 there has been no significant long-term trend in Ap.

  44. The most important words in the abstract, IMHO…

    “…century-scale cold summer anomalies, of which the Little Ice Age (LIA) is the most extreme…”

    So, coming after the “most extreme” “cold summer anomaly” might explain a little warming. Right?

  45. Sunspot link to Earthquakes ??? This could only happen if the Earth and Sun were strogly linked by magnetic & electric forces. This is getting dangerously close to Electric Universe / Plasma Universe theory !!

  46. ok great….now the science is really settled

    there was a LIA, it was caused by volcanoes…
    …which masked the warming that started before the LIA………..

    Only now that warming has greatly accelerated because of a trace gas…
    …that was a whole lot higher in the ice ages

    ..and the warming has stopped for the past 15 years
    because, because………..

    ..but it’s going to come back…with a vengeance..right after they adjust Envisat to show even more sea level rise

    I have a hard time believing science when they advertise a new medicine….
    …and it’s immediately followed by an ad from an attorney

  47. “With a flat TSI, they were able to replicate the temperature pattern based on the volcanoes at that time. By not trying to discount solar variation, they actually proved there is very little.”

    No, they proved that the climate models do not account for solar variation.

  48. I still prefer it that they’re trying to explain the LIA rather than deny its existance.

    Should we now place NCAR/UCAR firmly in the “Mann’s hockey stick is full of it!” camp with the rest of the right-thinking people?

  49. ggm says:
    January 30, 2012 at 1:56 pm
    Sunspot link to Earthquakes ??? This could only happen if the Earth and Sun were strogly linked by magnetic & electric forces.
    There is no evidence for such a link. Here [ http://www.leif.org/research/Earthquake-Activity.png ] is the number of strong earthquakes [two different data sets - Pager and Centennial] as a function of days from a change in the interplanetary magnetic field as it sweeps past the Earth [top] and from the start of a geomagnetic storm [middle]. The bottom panel shows the response of the aa index [similar to ap] to those same storms.

  50. From the Wikipedia page on the Kuwae eruption

    Climatic consequences of the 1452 – 1453 event

    A study by Dr Kevin Pang of the Jet Propulsion Laboratory[7] drew on evidence found in tree rings, ice cores and in the historic records of civilizations in Europe and China. Oak panels of British portrait paintings had abnormally narrow rings in 1453–55.
    In Sweden, grain tithes fell to zero as the crops failed; western U.S. bristlecone pines show frost damage in 1453; and the growth of European and Chinese trees was stunted in 1453–57.
    According to the history of the Ming Dynasty in China in the spring of 1453, “Nonstop snow damaged wheat crops.” Later that year, as the dust obscured the sunlight, “Several feet of snow fell in six provinces; tens of thousands of people froze to death.”
    Early in 1454, “it snowed for 40 days south of the Yangtze River and countless died of cold and famine.” Lakes and rivers were frozen, and the Yellow Sea was icebound out to 20 km from shore.
    The eruption occurred just before the Fall of Constantinople, the last bastion of the once-mighty Byzantine Empire. The Ottoman Turks, led by Sultan Mehmed II, laid siege to the city on April 5, 1453, and conquered it on May 29. Pang found mention of the volcano’s aftereffects in chronicles of the city’s last days. Historians noted the city’s gardens that spring produced very little. On May 25, a thunderstorm burst on the city: “It was impossible to stand up against the hail, and the rain came down in such torrents that whole streets were flooded”. On the night of May 22, 1453, the moon, symbol of Constantinople, rose in dark eclipse, fulfilling a prophecy of the city’s demise. Four days later, the whole city was blotted out by a thick fog, a condition unknown in that part of the world in May. When the fog lifted that evening, “flames engulfed the dome of the Hagia Sophia, and lights, too, could be seen from the walls, glimmering in the distant countryside far behind the Turkish camp (to the west),” historians noted. Residents of the city thought the strange light was due to reflection from a fire set by the Turkish attackers. Pang said, however, such a “fire” was an optical illusion due to the reflection of intensely red twilight glow by clouds of volcanic ash high in the atmosphere. Many such false fire alarms were reported worldwide after the 1883 Krakatoa eruption in Indonesia.
    “I conclude that Kuwae erupted in early 1453,” Pang said. “The residual volcanic cloud could have made the apocalyptic June 1456 apparition of the Comet Halley look ‘red’ with a ‘golden’ tail, as reported by contemporary astronomers.”

  51. Any mention of ‘powerful computer models’ in the area of Climatology triggers my giggle reflex.

  52. Spot the Difference.
    Anthony writes:
    “New paper speculates on volcanoes during the Little Ice Age”

    Richard Black Environment correspondent, BBC News writes:
    “The Little Ice Age was caused by the cooling effect of massive volcanic eruptions, and sustained by changes in Arctic ice cover, scientists conclude.”

    And what conclusion will the BBC audience come to?

  53. Richard M wrote: “Also, we had a couple of fairly good sized volcanoes in the last 30 years. While they did drop temps for a year or so, the temps bounced back right away.”

    Given the scale of natural year-on-year variability, can we really know what would otherwise have been the case? Look at the UAH-MSU graph wiggling around: http://www.junksciencearchive.com/MSU_Temps/UAHMSUglobe.html

    Can we really say that, but for the 1991 Pinatubo eruption the UAH-MSU would have been 0.5C higher? The wicked warmists allow themselves the luxury of pointing to an untick or downtick and declaring, “THIS was caused by THAT.” We sceptics need to be more rigorous.

  54. If I remember correctly, the freezing of the Thames in London was partly due to the old London Bridge, which greatly restricted the river flow and allowed the ice to build up. So even if the temperatures dip to the same extent as they did then it is unlikely to result in complete freezing of the river again. Personally i hope the temperatures don’t go down that much! I prefer a warmer climate with plenty of CO2!

  55. I remain puzzled as to how the authors make the attribution of the Little Ice Age to volcanic eruptions when the eruptions they site could not make very much more than a slight dip in temperatures worldwide.

    To cool down the Earth over a period of centuries would require something near a supervolcano in size and explosivity.

    I think what they’ve actually done (with powerful climate models) is rediscover the old theory of “post hoc ergo propter hoc”

  56. Leif Svalgaard says:
    January 30, 2012 at 2:16 pm

    Dang it Dr. Svalgaard……you even included sigma. Blows what I thought I knew right out of the water again…..

    Thank you.

  57. Not buying this at all. I think they need more authors as well. They only have 4 modeling points per author. Another over-fitted paper.

  58. So which volcano are they blaming the “travesty” on?

    Maybe this begs a cartoon showing MM trying to smuggle a frakking drill in to Yellowstone.

  59. The year: 1815

    The Tambora volcano in Indonesia erupted on April 5th with the largest eruption on April 10th and 11th. The volcanic rain, meteotsunami and climate change killed livestock and destroyed crops. More than 92,000 people died, maybe 100,000, from starvation making this eruption the most deadly on record. Tambora was 100 times the power of the Vesuvius eruption of 79 AD. Tambora is 14,107 feet high and is located on the Sumbawa Island of Indonesia. The chamber with centuries accumulation of magma was emptied of its contents. The ash and gases caused substantial climate change lowering global temperatures one degree, denyig two summers and lasting through the next year. Scientists have calculated that Tambora has erupted three times before. The 1815 eruption of the Tambora volcano is one of four eruptions in the past 10,000 years to have been assigned a Volcanic Explosivity Index of 7. This Tambora eruption was the most powerful eruption in recorded history.
    _______________________

    LIA and short freezing seasonal time fames in years show this remarkable link to volcanic activity. However these times of climatic temperature drops always are linked as to how much out gassing of dust clouds projected into the atmosphere remain air borne over longer time durations thereby blocking sunlight over vast areas of continents.

    To be fair: LIA and MWP are shown on all reconstructions. The extent of those times are firmly reconstructed and these times are well known by all climate scientists. It is a matter of interpretation just how widespread those warming periods were. The controversy of increasing temperatures rests not on a 20th century upper boundary of a hockey stick. It all goes back to 1998 when the world for the first time experienced a record temperature spike. However what has happened contrary to opinion is that the hottest years since 1998 are still happening despite a record low sun activity along with a record breaking LA Nina (2010/2011) that is one of the highest temperature rated La Nina since records began. Indeed a temporal drop in temperatures does exist.

    What we do know is this:

    1. A quiet cycle sun does last forever.
    2. We do have ongoing La Ninas forever
    3. We are increasing levels of CO2 that contribute to warming/ warmer climate.
    4. Out gassing of dust have occurred over this present period of time from volcanic activity.

  60. “The researchers set solar radiation at a constant level in the climate models. The simulations indicated that the Little Ice Age likely would have occurred without decreased summer solar radiation at the time”

    The correlation between glacier/temperature changes with solar changes during the last 1000 year is well established.
    See for example

    Or better, read my booklet

    http://scienceandpublicpolicy.org/images/stories/papers/originals/climate_change_cause.pdf

    for example figure 6 and 7, and appendix D, E and F.

    There exists also a volcano cooling effect, of course. But its cooling capability on a multidecadal scale is at least 5 times smaller than the cooling from prolonged low solar activity.

    The problem is that this study uses a computer model to estimate the volcano effect, but it does not test first whether the computer model can reproduce the volcano cooling activity observed during the last 150 years!

    I have shown that these computer models greatly overestimate the volcano cooling when compared to the actual data. See for example my last paper discussed here

    http://wattsupwiththat.com/2012/01/09/scaffeta-on-his-latest-paper-harmonic-climate-model-versus-the-ipcc-general-circulation-climate-models/

  61. “…powerful computer climate models, provides new evidence in a longstanding scientific debate over the onset of the Little Ice Age. …”
    [emphasis added]
    While models may be very useful in making a decision or judgement call, it seems to me that the models cannot provide
    evidence of anything.
    And anyway, I’m certainly glad that they did not use “wimpy” computer models. /snark

  62. “The researchers set solar radiation at a constant level in the climate models. ”

    Except that solar radiation wasn’t at a constant level. You can also set the tree ring data at a constant level too, and then come up with the trend you want to show at the next IPCC conference. Poor old sun, never gets the recognition it deserves, Galilieo all over again.

  63. In order to give this study some perspective, the authors should list all volcanic eruptions between say 1400 and 1900, the historical written evidence for these including death toll and an estimate of the amount of material injected into the atmosphere.

    Given that the two biggest eruptions that took place these past 1000 years took place in the 19th century (Tambora in 1815 with 71,000 deaths and Krakatoa in 1883 with 35,000 deaths not forgetting Galunggung 1822 with 4,000 deaths), why did the LIA not extend further into the 19th century?

  64. ggm

    Camburn

    I may be guilty of spreading miss-information for many other matters. but for this one you have to blame the NASA

    There is strong evidence of electromagnetic processes responsible for earthquake triggering, that we study extensively. We will focus here on one correlation between power in solar wind compressional fluctuations and power in magnetospheric pulsations and ground H component fluctuations.

    Geophysical Research Abstracts,Vol.8,01705, 2006;Lab for Solar and Space Physics, NASA Goddard Space Flight Center,Greenbelt, MD http://www.cosis.net/abstracts/EGU06/01705/EGU06-J-01705.pdf

  65. I’ve read before that the little ice age coincided with a period where there were very little sunspots and that when the sunspots returned, it got warmer. As such, I don’t buy this study at all. I think they are looking to science to dismiss any solar connection for the past warm and cool periods and this is one such example.

    And I thought the hockey stick got rid of the LIA?

  66. dave38 says:
    January 30, 2012 at 3:00 pm
    //////////////////////////////////////////////
    I think the river flow was different back then and that this assisted the freezing.

    I am not sure whether the river was narrower, or whether it was partly blocked as you say or whether it was more silted up or less tributaries connected with it. No doubt there could be a variety of reasons behind the differences in flow rate..

  67. thingadonta:
    Solar radiation does NOT vary much from cycle to cycle. The light composition within the TSI does.

  68. Mount Fuji, the highest in Japan (3776 m), also erupted in 1707 and caused harvest failure and famine.

  69. OK, how much lead and lag did this volcano induced climate change display?

    What happens if they incorporate the history of volcano activity as an input to the climate models? Does the purported sensitivity to CO2 go up or down?

    It is not enough to come up with an alternate explanation for LIA, it has to be used to improve model accuracy.

  70. Brent Hargreaves says:
    January 30, 2012 at 2:57 pm
    ///////////////////////////////////////////////
    Brent

    I am with you on this as you will note from my post of 3:50pm.

    For example looking at the BEST data set for 1860 to 1890:

    http://www.woodfortrees.org/plot/best-upper/from:1860/to:1890

    Can one really see Krakatoa (1883) in this data given the natural variabiitly that appears to be in that set?

    As a sceptic, I question the effects of volcanos. I can certainly accept the principle but I do feel that volcanic eruptions can be over-hyped by the warmist to overcome inconvenient data.

  71. During the depths of the Little Ice Age;

    http://www.eh-resources.org/timeline/timeline_lia.html

    http://en.wikipedia.org/wiki/Little_Ice_Age

    there were more major volcanoes. i.e. ones with a Volcanic Explosivity Index (VEI) rated 5 or higher;

    1580 ± 20 – VEI6 – Billy Mitchell
    1586 – VEI5? – Kelut, Java
    1593 – VEI5? – Raung, Java
    1600 – VEI6 – Huaynaputina
    1625 – VEI5 – Katla
    1640 – VEI5 – Komaga-Take, Japan
    1641 – VEI6 – Mount Parker
    1650 – VEI6 – Kolumbo, Santorini
    1660 – VEI6 – Long Island (Papua New Guinea)
    1663 – VEI5 – Usu, Japan
    1667 – VEI5 – Shikotsu (Tarumai), Japan
    1673 – VEI5? – Gamkonora, Halmahera
    1680 – VEI5? – Tongkoko, Sulaw

    as compared to a period such as our prior century:

    1902 – VEI6(?) – Santa Maria, Guatemala
    1907 – VEI5 – Ksudach, Kamchatka
    1912 – VEI6 – Novarupta (Katmai)
    1932 – VEI5+ – Azul, Cerro (Quizapu)
    1956 – VEI5 – Bezymianny, Kamchatchka
    1980 – VEI5 – St Helens, US
    1982 – VEI5 – El Chichon, Mexico
    1991 – VEI6 – Pinatubo, Philippines

    The effects of volcanoes on Earth’s climate are well know, e.g. “the 1991 explosion of Mount Pinatubo, a stratovolcano in the Philippines, cooled global temperatures for about 2–3 years.

    In 1883, the explosion of Krakatoa (Krakatau) created volcanic winter-like conditions. The next four years after the explosion were unusually cold, and the winter of 1887 to 1888 included powerful blizzards.Record snowfalls were recorded worldwide.

    The 1815 eruption of Mount Tambora, a stratovolcano in Indonesia, occasioned mid-summer frosts in New York State and June snowfalls in New England and Newfoundland and Labrador in what came to be known as the “Year Without a Summer” of 1816.

    A paper written by Benjamin Franklin in 1783 blamed the unusually cool summer of 1783 on volcanic dust coming from Iceland, where the eruption of Laki volcano had released enormous amounts of sulfur dioxide, resulting in the death of much of the island’s livestock and a catastrophic famine which killed a quarter of the population. Temperatures in the northern hemisphere dropped by about 1 °C in the year following the Laki eruption.

    In 1600, the Huaynaputina in Peru erupted. Tree ring studies show that 1601 was cold. Russia had its worst famine in 1601 to 1603. From 1600 to 1602, Switzerland, Latvia and Estonia had exceptionally cold winters. The wine harvest was late in 1601 in France, and in Peru and Germany wine production collapsed. Peach trees bloomed late in China, and Lake Suwa in Japan froze early.[4]

    In 1452 or 1453, a cataclysmic eruption of the submarine volcano Kuwae caused worldwide disruptions.

    The Great Famine of 1315–1317 in Europe may have been precipitated by a volcanic event,[5] perhaps that of Kaharoa, New Zealand, which lasted about five years.[6]

    The extreme weather events of 535–536 are most likely linked to a volcanic eruption.”

    http://en.wikipedia.org/wiki/Volcanic_winter

    If there is a potential climatic catastrophe we should be prepared for, a major volcanic eruption seems like a good candidate…

  72. I have been investigating the link to solar flares – there appears to NO link whatsoever.

    Many proponents of solar warming pull ad hoc hypothesis out of the hat. This has been the strategy of Scafetta and West over the years, and we have no illusion that our paper will actually put them to silence. However, the only scientifically valid strategy to confront these new hypotheses is to shoot down every new missile as they come in, using the most advanced weapons at hand. We believe that this operation was successfully accomplished with respect to the complexity linking hypothesis, but there will be many more battles to be fought until the issue of the contribution of solar variability to recent global warming is settled.”

    More information: M. Rypdal and K. Rypdal. “Testing Hypotheses about Sun-Climate Complexity Linking.” Physical Review Letters 104, 128501 (2010). DOI:10.1103/PhysRevLett.104.128501

    ______________________

    My Opinion:

    This link to solar and its random effects can only be settled if we take yet another 15 year slab of the evidence from 2012 to 2027. If this period continues to warm above and beyond negative forcing inclusive of those who are unable to accept the core science of AGW many theories are going fall – and very hard.

    I have it on good good knowledge and advice that (cmae fro0m one of them at a hEartland Conference) two scientists who are mildest will support the AGW hypothesis ( according to IPPC estimates) of an upper 2 degree Celsius by the end of this century if temperatures continue to rise over this period.

    I also understand if those estimates are correct then global action will turn to addressing all these issues and the debate between non-warmest and warmest will be all over.

  73. Nicola Scafetta says:
    January 30, 2012 at 3:33 pm
    ——————————————

    I stumbled across that research from Heidelberg University a couple of weeks ago,

    http://www.uibk.ac.at/geologie/pdf/spa12.pdf

    and I was very surpirsed, that such precise reconstructions of the last millenium exist, that they are NOT local (same results, same peaks from spaleothemes in Northern Europe, North Atlantic, China, Chile,…) and that they are so well correlated with the sun’s output.

    Actually, many questions in climate science have been answered with that – but nobody cares…

  74. The way this page renders on my browser the phrase “computer simulations conducted for the study” appears under the picture of the person picking at the rocks.

    Are you sure that this is not the correct caption for the photo?

  75. If we take this a step further, would that mean there is the potential for really low activity cycles, like 24 and 25 are projected to be, to set off eruptions of super volcanos like Yellowstone?

    Perhaps it was the Lake Toba eruption about 70,000 years ago that began the last ice age.

    http://en.wikipedia.org/wiki/Lake_Toba

  76. I understand the authors used a constant for solar output. Fine, my question is different:
    Has anyone validated the TSI measurements? I understand they claim .01% accuracy over the entire range using one instrument. At solar max when EUV is many times higher than usual, is this extra energy content really included in TSI accurately? Are other bands giving lower energy at that time to balance (or the EUV band too narrow to matter)? Perhaps measurements of many energy bands from other satellites could be used to check? I just don’t understand how a many-times increase in EUV can have so little overall effect…

  77. Isn’t the cause of the solar cycle and its variations, the gravitational effects between the sun and planets ?

    If the suns output can change as a result of gravity why can’t the earth’s behavior with respect to volcanoes and earthquakes ?

    As I understand things, solar activity is the result of “tides” within the Sun,
    Why can’t the earth have similar “tides” in the mantle ?

    I should certainly think minor effects on the mantle could have significant consequences in terms of volcanoes and earthquakes.

  78. “The study, which used analyses of patterns of dead vegetation, ice and sediment core data, and powerful computer climate models”… LOL

    Tropical volcanoes? Which ones? As if such surge in activity would only affect tropical volcanoes not others… If so, ash deposits would be easily found and dated. their mapping would indicate the extent of activity but that would mean real research… not running a model. Next time a volcanologist will be interested in monitoring the activity of some volcano, he’ll check dead vegetation in the Arctic and run a model… LOL

  79. Hey, wait a minute…’The model, which simulated various sea ice conditions from about 1150 to 1700 A.D., showed several large, closely spaced eruptions could have cooled the Northern Hemisphere enough to trigger the expansion of Arctic sea ice.’.
    If one looks up major volcanic eruptions, there are not several large, closely spaced eruptions during the period they indicate. One 1258, one 1280, one 1310….Those are not closely spaced.
    The text (so far, the study is ‘in press’) does not show that they actually identified and verified any such set of eruptions, only periods of sudden cold (dead plants, thicker ice layers).
    I will hold my breath until the study is available….I want to see if they can show evidence of the blamed ‘several large, closely spaced eruptions’.

  80. @ rossbrisbane says: January 30, 2012 at 4:07 pm and M. Rypdal and K. Rypdal’s paper.

    The paper by Rypdal and Rypdal criticizing one of my 2003 papers has been properly rebutted
    N. Scafetta and B. J. West, “Comment on `Testing hypotheses about Sun-climate complexity linking’ ” Phys. Rev. Lett. 10.1103/PhysRevLett.105.219801 (2010).

    http://www.fel.duke.edu/~scafetta/pdf/PRL2010-e219801.pdf

    Rypdal and Rypdal simply took apples for oranges.

    @Manfred says: January 30, 2012 at 4:11 pm
    Actually, many questions in climate science have been answered with that – but nobody cares…

    Right now it is very difficult for good papers to get a visibility in the politicited media news!

    In any case, there are exceptions!

    http://www.forbes.com/sites/larrybell/2012/01/10/global-warming-no-natural-predictable-climate-change/

  81. Just The Facts

    “During the depths of the Little Ice Age…there were more major volcanoes. i.e. ones with a Volcanic Explosivity Index (VEI) rated 5 or higher;..”

    Thanks for that. I have been trying ti get up the motivation of wading into the GVP site and digging that out.

    My gut feel is that the astronomical connection to plate tectonics and volcanoes is a load of carp… but that large volcanic events during a low in solar activity is the “two push” event that triggers the really cold events.

  82. Billy Liar says:
    January 30, 2012 at 3:43 pm

    Yep……saw it after it was posted but no way to correct.

  83. Robert Brown says:
    January 30, 2012 at 12:04 pm

    One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism?
    ——
    An interesting question. From an energy point of view, it doesn’t seem likely — I’ve estimated the power associated with magnetic induction and although it is a very large number, it is a very small number compared to the size the Earth. Of course, I could have made a mistake in my arithmetic, but I wouldn’t think that the forces are large compared to, say, tidal forces.

    rgb

    ========================

    @ Robert Brown and whoever he was responding to

    I believe there is a strong possibility that the tetonic plates have a direct influence on the magnetic fields of any solar induced magnetic flux.

    Several years age I was playing around with a compass (needle type). Don’t even ask why I was doing this. By placing it on the body of my car, as I moved it across the hood it remained fairly accurate. As it was moved to the edge of the hood the needle changed considerably. Interesting. I tried it on the trunk, fender, and every sheet metal object available. Same effect. I don’t remember the orientation of the needle but I think it may have aligned with the edge of the metal. If there is some valid reason for this, then the possibility exists that the plate tetonics could very well effect the magnetic field at the intersection, or break if you will. Just my observations. The geomagnetic forces on the Earth generated by the sun are possibly much greater than we can imagine and may be the ‘rabbit in the hat’.

  84. “Does a reduced solar-magnetic influence prompt more volcanism?”

    The typical scenario for large eruptions is that they occur at warm blasts after colder months, most often after colder N Hemisphere winters. There are few exceptions to this pattern.

  85. Camburn says:
    January 30, 2012 at 3:57 pm

    Solar radiation does NOT vary much from cycle to cycle. The light composition within the TSI does.

    And this is the area you and others should bring yourself up to speed on. UV radiation varies over the solar cycle by very large amplitudes. EUV (100%), FUV (30%) and MUV (1%)

    Solar UV changes are responsible for large chemical changes in all levels of our atmosphere above the troposphere. These changes also affect pressure patterns and jet streams in the lower levels.

    http://tinyurl.com/2dg9u22/?q=node/236

  86. Manfred says:
    January 30, 2012 at 2:47 pm
    Is there any data for the Dalton minimum 1790-1830 ?
    There is scattered data. Not enough for a meaningful time series.

    Camburn says:
    January 30, 2012 at 3:04 pm
    Dang it Dr. Svalgaard……you even included sigma. Blows what I thought I knew right out of the water again…..
    “It is not what you know that gets you in trouble, but what you know that ain’t” Mark Twain.

    thingadonta says:
    January 30, 2012 at 3:37 pm
    “The researchers set solar radiation at a constant level in the climate models. ”
    Except that solar radiation wasn’t at a constant level.

    No, they don’t usually set it constant, see e.g. slide 11 of http://lasp.colorado.edu/sorce/news/2011ScienceMeeting/docs/presentations/6b_Cahalan_Sedona_9-15-2011.pdf

    Paul Wanamaker says:
    January 30, 2012 at 4:29 pm
    I just don’t understand how a many-times increase in EUV can have so little overall effect…
    Because the energy involved is so small. It is like judging a billionaire’s wealth by the varying loose change in his pocket.

  87. “The model showed that sustained cooling from volcanoes would have sent some of the expanding Arctic sea ice down along the eastern coast of Greenland until it eventually melted in the North Atlantic. Since sea ice contains almost no salt, when it melted the surface water became less dense, preventing it from mixing with deeper North Atlantic water. This weakened heat transport back to the Arctic and created a self-sustaining feedback on the sea ice long after the effects of the volcanic aerosols subsided, according to the simulations.”

    No one seems to have picked up on the nonsense of this part of the argument to provide the necessary feedback required to maintain the hypothesis.

    Don’t we get freezing of the sea off the east coast of Greenland every winter anyway and it does not seem to interfere with the thermohaline circulation? Indeed, the whole of the Arctic happily expands and contracts annually without this positive feedback being observed.

    And in the preceding winter season to the summer season melt in which the surface water became less dense, the sea would have frozen more making the surface water more dense and thus aiding transportation.

    And how can the effect be maintained from season to season? The circulation would have replenished itself in the time interval from one season to another. The slate would have been wiped clean with the progression of each season.

    Stuff and nonsense. I am going to bed.

  88. Guys & Dolls, be cool; what this paper is really trying to state is “We need money!! Give us millions to study this further or we are surely doomed!!” (Alarmism implied in the way they leave disaster unknown lurking)

    Some facts (cough cough, it’s hard to call anything from this article that)

    “…The persistence of cold summers following the eruptions is best explained by a subsequent expansion of sea ice and a related weakening of Atlantic currents, according to computer simulations conducted for the study…”

    Why is it “best” explained by? Gut feeling or is it just that the compter models are already programmed around weakening Atlantic currents? (my speculation based on their speculation).

    “…If the climate system is hit again and again by cold conditions over a relatively short period—in this case, from volcanic eruptions—there appears to be a cumulative cooling effect.”

    “Our simulations showed that the volcanic eruptions may have had a profound cooling effect,” says NCAR scientist Bette Otto-Bliesner, a co-author of the study. “The eruptions could have triggered a chain reaction, affecting sea ice and ocean currents in a way that lowered temperatures for centuries.”…

    (my emphasis on all of those confidence inspiring words)

    Sure and I may become a rich millionaire climate scientist. yeah, right…

    The annual layers in the cores—which can be reliably dated by using tephra deposits from known historic volcanic eruptions on Iceland going back more than 1,000 years—suddenly became thicker in the late 13th century and again in the 15th century due to increased erosion caused by the expansion of the ice cap as the climate cooled.

    Say again? Increased erosion when the ice cap expanded? Is this a climate scientist way of saying that it rained/precipitated more? Or that the ice cap melted more (while expanding at the same time, but it beats me how that proves ice cap expansion).

    To reiterate; liberal use of conditional modifiers, fancy speak about fuzzily defined findings and the translation is give us more money so we can study this more. Yeah, the premise is possible, even plausible, but the study described above is far from convincing.

  89. “This weakened heat transport back to the Arctic and created a self-sustaining feedback on the sea ice long after the effects of the volcanic aerosols subsided, according to the simulations.”

    OK, so what put an end to the “self-sustaining feedback” that prolonged the LIA after the volcanic aerosols subsided? Was there an increase in CO2? Was it the Sun? Or did something else happen to end the feedback? It just stands to reason that If the feedback was caused by “expanding Arctic sea ice” and was “self-sustaining” after the volcanic activity subsided, then something had to happen to reversed it. What was it?

  90. There appears to be evidence that solar changes can and do cause an increase in volcanic eruptions.

    The volcanic eruptions correlate with cyclic warm periods followed by cold periods that correlate with cosmogenic isotope changes that are known to be caused by a slow down in the solar magnetic cycle.

    It seems likely as there are 23 abrupt climate change events each of which has coincidental cosmogenic isotope changes associated with them (the cosmogenic isotope changes are known to be caused by solar magnetic cycle changes) that the sun is the cause of what is observed. There is additional evidence to support that hypothesis.

    http://www.agu.org/pubs/crossref/2003/2003GL017115.shtml

    Timing of abrupt climate change: A precise clock by Stefan Rahmstorf

    Many paleoclimatic data reveal a approx. 1,500 year cyclicity of unknown origin. A crucial question is how stable and regular this cycle is. An analysis of the GISP2 ice core record from Greenland reveals that abrupt climate events appear to be paced by a 1,470-year cycle with a period that is probably stable to within a few percent; with 95% confidence the period is maintained to better than 12% over at least 23 cycles. This highly precise clock points to an origin outside the Earth system; oscillatory modes within the Earth system can be expected to be far more irregular in period.

    The observational evidence shows what is cause and what is effect.

    Geological processes including volcanic eruptions are not cyclic with precise periods. Eruptions and earthquakes are random. (i.e. To create cyclic volcanic eruptions requires an external cyclic forcing agent that causes the volcanic eruptions. As noted in the paper below there is simultaneous eruptions in both hemisphere during the cold periods. The hemispheres are geological separated in terms of volcanic activity for geological forcing mechanisms.)

    The cold periods are hundreds of years long. Volcanic eruptions cool for a few years. Abrupt changes in the geomagnetic field also correlate with the volcanic eruptions and the cold phases.

    It is the reduction in the geomagnetic field by a factor of 3 to 5 which causes the long term cold periods (termination of the interglacials and abrupt cold periods during the glacial phases, Heinrich events.) The Younger Dryas abrupt cold period lasted more than 1000 years.

    A restart of the solar cycle after a magnetic cycle interruption is what causes the increase in volcanic activity and the change in the geomagnetic field. There are burn marks on the surface (throughout the Northern Hemisphere, all continents) of the planet that correlate with the Younger Dryas cooling period. There is an aborted geomagnetic excursion (the geomagnetic field becomes weaken and non polar during an excursion and the field intensity drops by a factor of 3 to 5.) at the same time as the Younger Dryas and the are geomagnetic excursions at the termination of past interglacials.

    http://www.pnas.org/content/101/17/6341.full

    Bipolar correlation of volcanism with millennial climate change
    Analyzing data from our optical dust logger, we find that volcanic ash layers from the Siple Dome (Antarctica) borehole are simultaneous (with >99% rejection of the null hypothesis) with the onset of millennium-timescale cooling recorded at Greenland Ice Sheet Project 2 (GISP2; Greenland). These data are the best evidence yet for a causal connection between volcanism and millennial climate change and lead to possibilities of a direct causal relationship. Evidence has been accumulating for decades that volcanic eruptions can perturb climate and possibly affect it on long timescales and that volcanism may respond to climate change. If rapid climate change can induce volcanism, this result could be further evidence of a southern-lead North–South climate asynchrony. Alternatively, a volcanic-forcing viewpoint is of particular interest because of the high correlation and relative timing of the events, and it may involve a scenario in which volcanic ash and sulfate abruptly increase the soluble iron in large surface areas of the nutrient-limited Southern Ocean, stimulate growth of phytoplankton, which enhance volcanic effects on planetary albedo and the global carbon cycle, and trigger northern millennial cooling. Large global temperature swings could be limited by feedback within the volcano–climate system.

    This is evidence of five geologically separate volcanoes (separate magma chambers) erupting almost simultaneously and capturing a geomagnetic excursion during there period of eruption. The evidence is overwhelming. The problem is each piece of evidence is a separate scientific specialty. There is additional evidence from an astrophysical standpoint to explain how and why the sun can leave burn marks on the surface of the planet, abruptly change the geomagnetic field, and can cause a bipolar increase in volcanic activity.

    http://www.agu.org/pubs/crossref/2006/2006GL027284.shtml

    Geomagnetic excursion captured by multiple volcanoes in a monogenetic field

    Five monogenetic volcanoes within the Quaternary Auckland volcanic field are shown to have recorded a virtually identical but anomalous paleomagnetic direction (mean inclination and declination of 61.7° and 351.0°, respectively), consistent with the capture of a geomagnetic excursion. Based on documented rates of change of paleomagnetic field direction during excursions this implies that the volcanoes may have all formed within a period of only 50–100 years or less. These temporally linked volcanoes are widespread throughout the field and appear not to be structurally related. However, the general paradigm for the reawakening of monogenetic fields is that only a single new volcano or group of closely spaced vents is created, typically at intervals of several hundred years or more. Therefore, the results presented show that for any monogenetic field the impact of renewed eruptive activity may be significantly under-estimated, especially for potentially affected population centres and the siting of sensitive facilities.

    http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf

    http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf

    Also, we wish to recall that evidence of a correlation between archeomagnetic jerks and cooling events (in a region extending from the eastern North Atlantic to the Middle East) now covers a period of 5 millenia and involves 10 events (see f.i. Figure 1 of Gallet and Genevey, 2007). The climatic record uses a combination of results from Bond et al (2001), history of Swiss glaciers (Holzhauser et al, 2005) and historical accounts reviewed by Le Roy Ladurie (2004). Recent high-resolution paleomagnetic records (e.g. Snowball and Sandgren, 2004; St-Onge et al., 2003) and global geomagnetic field modeling (Korte and Constable, 2006) support the idea that part of the centennial-scale fluctuations in 14C production may have been influenced by previously unmodeled rapid dipole field variations. In any case, the relationship between climate, the Sun and the geomagnetic field could be more complex than previously imagined.

  91. I have to ask again:
    Would heavy volcanic emissions mask sunspots, resulting in low sunspot numbers?

    I’m skeptical of global warming, but I think it’s an interesting question. I would also like to see a time-line with all the volcanic eruptions shown along side the cooling/warming periods.

  92. Nicola Scafetta

    Post paper:

    1. Fitting a curve with a simple model using physically unconstrained parameters is simply not a scientific process,
    2. It fails with a hind cast test.
    3. Assumed 60 year cycle which was the basis of the L&S model does not show up in Loehle’s own millennial global temperature reconstruction – a glaring contradiction.
    4. Correlation is not causation; all you have demonstrated is a non-physical curve fitting exercise for a resultant correlation between cycles and global temperature.
    5 Finding a correlation between two very limited references and global temperature, doesn’t mean these variables are causing global warming. WHY?
    6. There is NO provable physical mechanism shown on which to base the model – yes it is a model fit but it proves nothing. We all know models – bad bad bad and ever more bad when it comes to a new hypothesis.
    7. Any model must firstly identify a realistic physical range of data before running that model.

    As nothing physically matching can be identified by doing standard tests, just like Spencer before them, all you are doing is playing pointless curve fitting games, and using results to draw unsubstantiated conclusions.

    Herein it for the reader to understand when alternatives on climate theories are presented. Sort of like the light bulb revelation everyone needs a good dose of occasionally.

    Endless speculations about our complex climate does nothing. That is difference between a scientific model and well – just another model anchored to prove a pre-conception.

    I maintain this does not pass proper scrutiny

  93. rossbrisbane says:
    January 30, 2012 at 7:31 pm
    Nicola Scafetta [...]
    I maintain this does not pass proper scrutiny

    Plus as has been discussed on other WUWT threads, the correlations are against flawed data to begin with.

  94. adolfogiurfa said @ January 30, 2012 at 1:32 pm

    @M.A.Vukcevic says:
    January 30, 2012 at 1:06 pm
    Really important!, you are being a Galileo Galilei
    However: You are being, like him, blasphemous!. How do you dare to doubt of the holy dogmas of Climate Change Church and the sainthood of its most renowned bishops?
    Your publications will be included in the INDEX!!

    Are you accusing Vukcevic of insulting the Pope? That’s not very nice…

    Hint: Galileo Galileo was never, ever accused of blasphemy. He was pious to a fault and rather famous for his sermons. Galileo insulted the Pope by putting the Pope’s words into the mouth of Simplicio (literally idiot). The Inquisition couldn’t decide whether or not this was heresy and found Galileo “vehemently suspected of heresy”.

    When are people around here going to learn that repeating falsehoods is not a good look?

  95. Leif Svalgaard says:
    January 30, 2012 at 7:11 pm

    paper published: http://www.leif.org/EOS/2011GL050168.pdf

    ======================

    I see M. Mann and G. Schmidt cited at the end of the last paragraph as well as in the acknowledgements. If you only know how to use a hammer, would you only seek nails to work with? Homage to the ‘Team’?

  96. Interesting paper! The authors conclude:
    “Together with climate modeling and supported by other proxy climate reconstructions, our
    results suggest that repeated explosive volcanism at a time when Earth’s orbital configuration resulted in low summer insolation across the NH acted as a climate trigger, allowing
    Arctic Ocean sea ice to expand. Increased sea ice export may have engaged a self-sustaining sea-ice/ocean feedback unique to the northern North Atlantic region that maintained suppressed summer air temperatures for centuries after volcanic aerosols were removed from the atmosphere. The coincidence of repeated explosive volcanism with centuries of lower-than-modern solar irradiance (Figure 2a) [Schmidt et al., 2011] indicates that volcanic impacts were likely reinforced by external forcing [Mann et al., 2009], but that an explanation of the LIA does not require a solar trigger.”

  97. rossbrisbane says:
    January 30, 2012 at 7:31 pm

    Nicola Scafetta…”all you are doing is playing pointless curve fitting games, and using results to draw unsubstantiated conclusions”

    Amazing putdown rossbrisbane! I suppose you would also trash using tide tables as well, since they are constructed using curve fitting games with the moon, sun etc.

  98. Ed_B writes,
    “Amazing putdown rossbrisbane! I suppose you would also trash using tide tables as well, since they are constructed using curve fitting games with the moon, sun etc.”

    No, you missed rossbrisbane’s point about needing a physical mechanism. Read his note again?

  99. “a related weakening of Atlantic currents, according to computer simulations ”

    Now, real science where you go out an take samples, shows that the Gulf Stream slows down during cold periods and speeds up during warm periods. Based on the viscosity of water, this makes sense. BUT, slowing of the current does not mean weakening, just a thicker fluid.

  100. rossbrisbane says:
    January 30, 2012 at 7:31 pm

    I have to agree with your analysis on this one. Nothing against Dr. Scafetta, but the tail does not wag the dog.

  101. Hopefully soon, I will be reading studies using gravitational variance, solar magnetic output and regional volcanic and earthquake data to monitor and study the worlds major trouble spots. I am not sure if there is ongoing monitoring of the gravitational variance of the earth from Grace or GOCE satelites but there should be.

    I am a layman way out of my field but I would like to say that the Sun’s magentic force has to play a role in the seemingly random dynamic under the crust. What other variables are there… tides, sea level, some unknown core dynamic? Teutonic plate movement begs the question about the force which moves the plates. It certainly cannot be utterly random. There is a system that has pattern. This is the reason the Grace and GOCE satellites were launched in the first place or am I all wet?

  102. eyesonu says:
    January 30, 2012 at 7:54 pm

    Swing the bat often enough and you are bound to hit the ball.

    It appears that some now have a batting average of .001%.

    Better than a no hitter.

  103. @ rossbrisbane says:

    Perhaps you need to read my papers before criticizing them. There are a little bit more complicated than simply curve fitting. And there exists a long discussion about the parameters adopted there.

    As shown in my papers, in particular in the latest one, the issue is that all GCMs adopted by the IPCC fail to properly reconstructing thae main patterns observed in the climate system including the steady temperature since 2000.

    Tell me, which GCM model agrees with the data? Which GCM passes proper scrutiny?
    Name one model, at least! You can look at the appendix of the paper and tell us your best choice.

    N. Scafetta, “Testing an astronomically based decadal-scale empirical harmonic climate model versus the IPCC (2007) general circulation climate models” Journal of Atmospheric and Solar-Terrestrial Physics, in press. DOI: 10.1016/j.jastp.2011.12.005.

    http://www.fel.duke.edu/~scafetta/pdf/Scafetta_models_comparison_ATP.pdf

    Studying the data and tring to understanding the dynamics they contain is the way science works. Science does not start with a fully understood mechanism, but with the data and their anaysis.

    @ Hi Leif, are you sure you did not miss something while in Japan? :)

    About the paper we are discussing in this post, thanks to Leif who put the paper of his web-site, I invite to look at their figure 2A,B and C.

    The increase of Ice cap expansion (figure 2C) between 1270 and 1500 is clearly in agreement with the solar pattern with two cool periods (maximum cap expansion) during the two prolonger solar minima Wolf (1270-1300) and Sporer (~1435) minima and a partial recovery between the two low solar mimima periods.

    About the volcano activity, please note the large vocano spike around 1258 and around 1460 (figure 2B). The 1258 volcano is presented at the precurson of the Little Ice age because it occurred a few decades before the large cap expansion peak between 1270 and 1300. However, the large volcano spike in 1460 occurred while the cap expansion was rapidly “decreasing” and it does not appear to have had any effect on climate.

    Thus, it is evident that the strong ice cup increase peak around 1430-1440 is related to the grand minima of the solar activity, and not to the volcano occurence, which happened after it around 1460. What do you think, Leif, about this point?

  104. Nicola Scafetta says:
    January 30, 2012 at 8:32 pm
    What do you think, Leif, about this point?
    I think you don’t need to try to hijack this thread too. We have already discussed the flaws of your papers, so no need to wallop in them again.

  105. Nicola Scafetta says:
    January 30, 2012 at 8:32 pm

    Doesn’t matter whether you think your models are crunching data in a meaningful way. If you have 20 equations with 24 unknowns, the best and most powerful computers with the most innovative algorithms ain’t gonna solve that baby.

  106. Leif, are you sleeping?

    I am talking about the paper currently addressed here. About my papers yo need some update.

    They claim that the large Ice cup increase during the LIA was caused by volcano activity and that the sun does not matter at all.

    Now, look at their figure 2A, 2B and 2C. In particular at the strong ice cup increase peak around 1430-1440. This occurred excactly at the minima of the grand solar Sporer Minimum. On the contrary, the major volcano activity peak occurred around 1460.

    So, my question is: was the strong ice cup increase peak around 1430-1440 caused more likely by the solar low activity of that time or by the great Volcano eruption of 20 years later?

    Note that no significant volcano eruptions occurred between 1350 and 1450

    Anthony, if you can, would you like to show Figure 2 in the paper by magnifying figure 2A, 2B and 2C between 1400 and 1500 with some arrow to indicate the points I am talking about?

  107. The author of the paper say:

    “The PDF peak between 1430 and 1455 AD corresponds with a large eruption in 1452 AD, although the ages of the three largest 5-year bins appear to precede the eruption date. In contrast to the earlier 13th Century peak, the second PDF peak occurs at the end of a 150-year interval of variable but falling snowline (Figure 2c), raising the possibility that the PDF peak plausibly reflects a brief natural episode of summer cold that preceded the large 1452 AD eruption.”

    “a brief natural episode of summer cold that preceded..”? Brief?, it was 20 years. Cased by what? by the volcano activity of 1452?!

  108. Nicola Scafetta says:
    January 30, 2012 at 9:14 pm
    that the sun does not matter at all.
    They probably got that right. But beware of your weasel words “at all”. Of course, the sun matter somewhat, like a little bit, but it is clear that the sun is not a major driver and that therefore the LIA has other, natural causes.

  109. “Because the energy involved is so small. It is like judging a billionaire’s wealth by the varying loose change in his pocket.”

    Thanks Leif for quantifying that for me! :)

  110. Paul Wanamaker says:
    January 30, 2012 at 9:55 pm
    “Because the energy involved is so small. It is like judging a billionaire’s wealth by the varying loose change in his pocket.”
    Thanks Leif for quantifying that for me! :)

    The EUV is less than 1/10,000 of the visible energy:

    http://lasp.colorado.edu/sdo/meetings/session_1_2_3/presentations/session2/2_01_Viereck.pdf

    and is absorbed above 100 km altitude where the density is less than 1/1000,000 of that at the surface. So up there there is a large effect [on a very small total mass] but it has no effect on the climate below. There is simply not enough stuff up there to make any difference.

  111. Paul Wanamaker says:
    January 30, 2012 at 9:55 pm

    “Because the energy involved is so small. It is like judging a billionaire’s wealth by the varying loose change in his pocket.”

    Thanks Leif for quantifying that for me! :)

    Instead of taking obscure comments from a scientist with obvious AGW bent, as gospel, I suggest you research the topic more thoroughly. EUV impacts the atmosphere directly down to 70 km as well as producing species that filter down to lower levels that control ozone production. FUV is responsible for ozone production down to 30km. EUV varies by 100% and FUV by 30% over the solar cycle.

    http://tinyurl.com/2dg9u22/?q=node/236

  112. Geoff Sharp says:
    January 30, 2012 at 10:31 pm
    EUV impacts the atmosphere directly down to 70 km
    slide 16 of: http://lasp.colorado.edu/sdo/meetings/session_1_2_3/presentations/session2/2_01_Viereck.pdf

    as well as producing species that filter down to lower levels that control ozone production.
    The density is so low [less than a 1/1000 of that in the stratosphere] that it doesn’t matter what ‘filters down’. The ozone is produced below 50 km in concentrations thousands of times larger than what is up there in the thermosphere. EUV has no influence on the climate.

  113. So four massive tropical volcanic eruptions (may have) triggered the Little Ice Age between 1275 and 1300 A.D, “…our simulations showed that the volcanic eruptions may have had a profound cooling effect…”
    Then again maybe not, “…frequent volcanic eruptions from 1100 to 1260 A.D. may have added to regional warming. Volcanic eruptions may have resulted in mild winters in northern and western Europe during High Medieval time…”.

    http://www.sciencedaily.com/releases/2003/10/031020055353.htm

    Authors of these papers may be laughing all the way to the bank.

  114. Leif Svalgaard says:
    January 30, 2012 at 10:58 pm

    as well as producing species that filter down to lower levels that control ozone production.
    The density is so low [less than a 1/1000 of that in the stratosphere] that it doesn’t matter what ‘filters down’. The ozone is produced below 50 km in concentrations thousands of times larger than what is up there in the thermosphere. EUV has no influence on the climate.

    I noticed you are now limiting your argument to EUV only and forget FUV. You have already been shown to be incorrect in this area and your opinion is in opposition to atmospheric scientists that are considered expert. This is not your field, how many papers have you written dealing with UV modulation in our atmosphere?

    Now you are down to dueling cherry picking. The LIA is a broad event lasting several hundred years and has likely nothing to do with solar activity anyway:

    I am merely pointing out your weak wiki statement is irrelevant and incorrect. Nicola is showing the growth in ice happens at the time of solar grand minimum (sporer) well before the volcanic event listed in the paper. There are 4 grand minima during the LIA, you need to be specific with the timing, the whole period was not cool.

  115. Manfred says:
    January 30, 2012 at 11:46 pm
    perhaps you are using the wrong reconstructions, what do you think about this ?
    “wrong”?
    You show a reconstruction from Austria. Is that supposed to be valid as Global Temperature?
    And BTW, the cosmic ray variation is not correct. The cosmic rays that reach the atmosphere vary foremost with the strength of the geomagnetic field rather than with solar activity. Here is the real cosmic ray variation: red curve at bottom: http://www.leif.org/research/INTCAL-Jasper.png and here for the past 10,000 years: http://www.leif.org/research/CosmicRays-GeoDipole.jpg The solar modulation are the small wiggles.

    Perhaps I should note that I’m not pushing the volcano idea. Just remarking that it is something that could be in the mix.

  116. Leif Svalgaard says:
    January 31, 2012 at 12:01 am
    Manfred says:
    January 30, 2012 at 11:46 pm
    perhaps you are using the wrong reconstructions, what do you think about this ?
    “wrong”?
    You show a reconstruction from Austria. Is that supposed to be valid as Global Temperature?

    ———————————————————

    The author claims it is global and from what he says, I think this is far superior to any other reconstruction. Here is my translation from a German TV discussion:

    Question: So you say we did have warmer times and colder times within those 10000 years ?

    Mangini: Yes, what we see from our data is indeed, that within 300 years it can go up and down, relatively or very fast, and there is variability in the temperature between 1 and 3 degrees, and I am very conservative here, it may well be within that range.

    Rahmstorf interrupting: locally

    Mangini: No, it is not local. We see this from the Alps up to Norway, all correlated and synchronous.

    Rahmstorf interruptung: This is local for me.

    Mangini: North-Atlantic synchronous, China synchronous, Chile synchronous, they are all synchronous, this is the great thing about stalagmites, because, as we can date them so well, we really see those peaks happening at all places at the same time.

    We have been working for about 10-15 years intensively on stalagmites and we even got now a research group from the DFG in Heidelberg to extract precipitation and temperature from stalagmites from the signals we see in them.

    Stalagmites grow layer upon layer and every layer is approximately 1 year and you can, if you measure the stable isotopes in a stalagmite, extract a formation over the growth period of a stalagmite. Stalagmites can be dated very well, there a many stalagmites, spread over all continents and these are very beautiful archives.

  117. Geoff Sharp says:
    January 30, 2012 at 11:48 pm
    I noticed you are now limiting your argument to EUV only and forget FUV.
    The FUV is absorbed in the E-layer and also does not get lower down and varies a lot less.

    You have already been shown to be incorrect in this area and your opinion is in opposition to atmospheric scientists that are considered expert.
    Nonsense. You misunderstand their papers. The FUV doesn’t have a significant climate signature either.

    This is not your field, how many papers have you written dealing with UV modulation in our atmosphere?
    Don’t fall in the trap believing that fields are so narrow that only somebody that doesn’t know anything can span them all. FUV absorption and its creation of the E-layer is something I have studied for decades. I use that for calibration of the sunspot number via the diurnal variation of the geomagnetic field.

    There are 4 grand minima during the LIA, you need to be specific with the timing, the whole period was not cool.
    The timing doesn’t matter as the temperature was low for hundreds of years and not related to solar activity: http://www.leif.org/research/Global-Temperatures-2000-yrs.png

  118. Geoff Sharp says:
    January 30, 2012 at 11:48 pm
    the growth in ice happens at the time of solar grand minimum (sporer) well before the volcanic event listed in the paper.
    If you care to actually read the paper you’ll learn that it does not claim that the LIA started in 1460:

    “Sea ice was rarely present on the North Iceland shelf from 800 AD until the late 13th Century, when an abrupt rise in sea-ice proxies suggests a rapid increase in Arctic Ocean sea ice export, followed by another increase 1450 AD, after which sea ice was continuously present until the 20th Century [Massé et al., 2008] (Figures 1 and 2e). The increase in sea ice north of Iceland at the start of the LIA, and its persistence throughout the LIA, supports our modeling experiments suggesting explosive volcanism and associated feedbacks resulted in a self-sustaining expanded sea-ice state beginning 1275–1300 AD. Additional support for regional cooling beginning in the late 13th Century comes from the inversion of temperatures measured in a borehole through the south dome of the Greenland Ice Sheet (Figure 1).”

  119. Nicola Scafetta says:
    January 30, 2012 at 9:14 pm

    Anthony, if you can, would you like to show Figure 2 in the paper by magnifying figure 2A, 2B and 2C between 1400 and 1500 with some arrow to indicate the points I am talking about?

  120. “Does a reduced solar-magnetic influence prompt more volcanism?”
    There has been speculation for some years that the rates of nuclear decay throughout the Earth may be modulated by varying solar neutrino fluxes.

  121. Leif Svalgaard says:
    January 30, 2012 at 8:06 pm
    eyesonu says:
    January 30, 2012 at 7:54 pm
    Homage to the ‘Team’?
    You can pay your own homage to whomever you like. How about some substance instead?

    ===================

    After reading your response and reviewing what I wrote, well……It does read quite different than what I meant. Sorry. This was a moment of ‘open mouth and insert foot’ on my part. It should have carried a ‘sarc’ tag.

    The other part of the original comment that I made would have better been stated as “If one only knows how to use a hammer, would one only seek nails to work with?” This was perhaps an ad hom directed at the ‘Team’s’ obsession with CO2.

    The paper by Miller et al is very interesting and appears to be very well supported.

    Effects of forcings on climate appears to take very long periods of time before the results reach an ‘equalibrium’ again or return to a normal, if there is such a thing as a normal. It’s a chaotic world we live on / in and I don’t think we have much to do with affecting it’s climate. There are much greater forces at work.

  122. Leif Svalgaard says:
    January 31, 2012 at 12:32 am

    If you care to actually read the paper you’ll learn that it does not claim that the LIA started in 1460:

    Missing the point again, you are claiming the Sporer started in 1460 which it clearly does not. Global cooling was well underway without volcanic activity. There is not enough volcanic activity to explain the 1300-1500 cold period, the paper is extremely poor and typical of AGW science. I would not align myself with such weak science, but do so at your own peril.

  123. Leif Svalgaard says:
    January 31, 2012 at 12:12 am

    The FUV is absorbed in the E-layer and also does not get lower down and varies a lot less.

    FUV penetrates down to a height of 30km (within the highest ozone band). FUV varies by 30% over the solar cycle. All of your arguments are false and show complete desperation to follow your agenda. I have already produced several papers that contradict you on another thread, but still you continue?

  124. Earthquakes are a Tectonic Plate event. Whilst there are gravitic influences from the Sun and Moon, they do drive ocean tides, the effect on Plate Tectonics would be minimal. I doubt if earthquakes are due to external drivers but I get a feed from USGS on earthquakes so perhaps some research can be done.

    The paper above puts the MWP temperature at 0.2C above today’s. Where do they get these figures. All research on the MWP put temperatures 2-5C above today’s. I cannot believe that there were no volcanic eruptions during this period to cool things down.

    This UCB team should get back to the drawing board and stop to drive research conclusions into what they wish to have happened.

  125. Next this you know, this team of “scientists” will propose to use sciene to trigger a massive volcanoe or two to offset global warming.

  126. One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism?
    ———
    Doesn’t seem plausible. Its 5 nTesla for the interplanetary field vs 50000 nTesla at the earth’s surface.

  127. I hate to rain on anyone’s parade – but in that picture of Mr Miller collecting ‘vegetation samples’ – those are actually – er – PEBBLES….

  128. Leif, your arguments prove as usual your biases asnd your lack of critical thinking.

    Look at the figure prepared by Geoff

    taken from their figure 2

    http://www.leif.org/EOS/2011GL050168.pdf

    It is evidentt that the strong peak of Ice cover (1430-1450) occured well before the great volcano eruption of 1452. So, unless you prove us that the time flow was inverted during that time, the strong peak of Ice cover (1430-1450) was not caused by the strong volcano activity in 1452, contrary to the poor opinion of these authors.

    Geoff, to better prove my point, may you prepare again the figure by adding the solar record depicted in Figure 2A too? Figure 2A, 2B and 2C should be together. You also need to add two red lines in concomitance of the two Ice cup peaks around 1275 and 1435, and show that they correspond to the two grand solar Wolf and Sporer solar minima exactly. Thank you.

    So, Leif, explain us the mistery of how a great volcano eruption occurred in 1452 could cause a strong cooling during the period 1430-1450.

    (Note Leif that only the solar recontruction and the data reported and referenced by the authors themselves count in this discussion. If you claim thattheir data are wrong, then you should blame the authors, not me, for having not investigated the issue properly and said non senses such as that solar activity is not important for explaining the LIA).

  129. Once again a model dependent paper got past peer review without including a discussion of the literature. The models are not good at melting snow and ice. The Andreas Roesch (2007) showed that ALL of the AR4 models had a positive surface albedo bias and were behind the observations in their simulation of the high latitude earlier snow melts and reduced snow cover fractions as well as forest stem shadowing of the snow cover. Recall that at the same time there was “alarm” about the Arctic ice cap melt and statements by Scambos and others that the models were 30 years behind. The Roesch effect was not small, the surface albedo bias amounts to more than 3 W/m^2, which is about 4 times larger than the energy imbalance for the 90s. By under representing the snow and ice melt response the models probably over represent the feedback from new ice from the volcanoes. They also will over represent the response to future warming, since they will eventually catch up with the snow and ice mounts, it is reduced, not missing, so the 3+W/m^2 will double the impact of the CO2 doubling, thinking linearly.

    The CCSM citations in the paper are from 2006. There is no discussion in the paper of the model diagnostic literature and whether the models have fixed this positive surface albedo bias problem reported in 2007 and known at the time AR4. So of course there is no error estimate for the problem. I thought at the time that the Roesch paper alone was enough to discredit model based conclusions and projections, given the easily appreciated magnitude and correlated nature of the bias. It is just one of dozens of papers diagnostic of issues with the models.

  130. F. Ross says:
    January 30, 2012 at 3:34 pm
    “…powerful computer climate models, provides new evidence in a longstanding scientific debate over the onset of the Little Ice Age. …”
    [emphasis added]
    While models may be very useful in making a decision or judgement call, it seems to me that the models cannot provide evidence of anything.
    And anyway, I’m certainly glad that they did not use “wimpy” computer models. /snark

    I agree with F. Ross. And did a journalist say that modeling was evidence or did a “scientist” make the connection?

  131. Leif Svalgaard says:

    “Of course, the sun matter somewhat, like a little bit, but it is clear that the sun is not a major driver and that therefore the LIA has other, natural causes.”

    Mind-boggling. Simply amazing!

  132. From the Tips & Notes you can find this post on the link between cosmic rays and volcanic activity:

    Ed Mertin says:
    January 31, 2012 at 12:41 am

    Explosive volcanic eruptions triggered by cosmic rays: Volcano as a bubble chamber 10.1016/j.gr.2010.11.004 : Gondwana Research | ScienceDirect.com

    http://www.sciencedirect.com/science/article/pii/S1342937X10001966

    http://www.deepdyve.com/lp/elsevier/explosive-volcanic-eruptions-triggered-by-cosmic-rays-volcano-as-a-3p053jxP0S

  133. Geoff Sharp says:
    January 31, 2012 at 2:33 am
    FUV penetrates down to a height of 30km (within the highest ozone band).

    Nicola Scafetta says:
    January 31, 2012 at 5:02 am
    It is evident that the strong peak of Ice cover (1430-1450) occured well before the great volcano eruption of 1452. </i?
    The LIA started in the 13th century.

  134. @Jim 12:25 pm:
    “Would heavy volcanic emissions mask sunspots, resulting in low sunspot numbers?”

    Jim, I just recently read where the (apparently) first observations of sunspots came during just such an event, when the sun was dimmed to the point they could SEE sunspots directly. My recollection is that this was only one or two hundred years before the first scientific notings of sunspots. Sorry, I can’t recall the source. And no mention if anyone went blind.

    smg

  135. @carol 12:22 pm

    Carol – Yeah, Clube and Napier had some strong evidence for all that. If you are interested in impacts, their history, their effects and the ongoing threat, check out http://www.CosmicTusk.com, a site that is a bit sporadic in postings, but has a lot of archived posts that might be worth your while.

    smg

  136. I like the UCAR site though it has some great articles and links. I never really did understand the effects of the Arctic Oscillation until I went to this link.

    http://www.washington.edu/news/articles/russian-river-water-unexpected-culprit-behind-arctic-freshening-near-u.s.-canada

    Seems that fresh water flowing from the Russian rivers has been diverted from the Eurasian basin between Russia and Greenland and is flowing into the Beaufort sea and adding 10 feet of fresh water to it. Grand effect is that this fresh water no longer protects the sea ice from the warmer Atlantic. When the oscillation stops they expect the fresh water path to switch back and sea ice to increase again. Something the BBC has never told me.

  137. IIRC, Pinatubo (1981) was a VEI 6, and El Chichon (1982) was a VEI 5. The effects of each of these lasted a scant 5-6 years before the stratospheric crud precipitated out. VEI4 eruptions such as Fuego (1975) cause barely a climatic ripple.
    There is only 1 known eruption in the 1275-1300 AD time frame – a ‘mere’ VEI 6 from Quilatoa in the Northern Andes. You just can’t hide eruptions that large or larger:
    en.wikipedia.org/wiki/List_of_large_volcanic_eruptions

  138. @ Leif

    Leif, as usually you do not reason as all or are extremely biased or simply dishonest!

    Yes, Leif, LIA started in the late 13th century with the solar Wolf minimum. Volcano did little.

    That volcanos do little (as shown in my papers, by the way) is clearly proven by the cool peak episode in 1430-1450 that agrees with the Sporer great minimum, not with the volcano eruption of 1452, as claimed by the authors, which occurred later.

    Look at the figure prepared by Geoff

    taken from their figure 2

    http://www.leif.org/EOS/2011GL050168.pdf

    Give a close look at fig2 and compare figure 2A, 2B and 2C.

    How can you be so biased on this so evident fact?

  139. sea-ice/ocean feedbacks ; is that albedo ? If yes could not albedo trigger the warming after the last glacial maximun in place of the CO2 feedback?

  140. Nicola Scafetta says:
    January 31, 2012 at 7:52 am
    Leif, as usually you do not reason as all or are extremely biased or simply dishonest!
    It would be refreshing if you could stick to the science. You miss the point of the paper: The LIA was largely self-sustaining once started so no close timing coincidences are required. This is the interesting idea that is explored.

  141. Leif, there is NO mapping and datation of pertaining ash deposits around identified tropical volcanoes. NONE.
    It would be indeed refreshing if many here could stick to science, i.e in this case good ol’ geology.

  142. TomRude says:
    January 31, 2012 at 8:36 am
    Leif, there is NO mapping and datation of pertaining ash deposits around identified tropical volcanoes. NONE.
    Seems to be an obvious research project then to provide such data.

  143. Really, Leif! Interesting idea?

    Supported by which empirical evidences? By the fact that a 20-year large ice cover increase peak from 1430 to 1450 was induced, according to the authors, by a volcano eruption occurred in their data in 1452 instead by the great solar Sporer minimum in 1420-1450 so evident in their own data?

    This paper proves nothing because the data that these authors present are not in agreement with the theory they would like to support. Nor they analyze the numerous papers showing the very good correlation with solar activity.

    This paper is nothing but another computer game with no scientific meaning.

    Read also the comment from

    http://www.wired.com/wiredscience/2012/01/volcanoes-and-the-little-ice-age-not-the-smoking-gun/

    where yo ucan read:
    “However, I look at that spectrum and don’t see what Miller et al. (2011) claim – sure, there is a big spike during the late 1200s/early 1300s (more on this later) and a single spike around 1450. However, what about the late 1700s/early 1800s? I’d say it is more “volcanically perturbed” than the 1430-1455 period they identify.”

    Come on Leif! you are not a so bad scientist, don’t you?

  144. LazyTeenager says:

    January 31, 2012 at 4:06 am

    One of the things I wonder about is that during low sunspot activity, does the reduced solar-magnetic influence have any effect on Earth’s plate tectoncs and vulcanism? Does a reduced solar-magnetic influence prompt more volcanism?
    ———
    Doesn’t seem plausible. Its 5 nTesla for the interplanetary field vs 50000 nTesla at the earth’s surface.

    Same sort of order of magnitude as CO2 in the atmosphere!

  145. Nicola Scafetta says:
    January 31, 2012 at 8:52 am
    This paper is nothing but another computer game with no scientific meaning.
    Sort of like your curve fitting with flawed data…

    Come on Leif! you are not a so bad scientist, don’t you?
    But you might be…

  146. Nicola Scafetta says:
    January 31, 2012 at 8:52 am
    This paper is nothing but another computer game with no scientific meaning.
    “[16] Our precisely dated records demonstrate that the expansion of ice caps after Medieval times was initiated by an abrupt and persistent snowline depression late in the 13th Century, and amplified in the mid 15th Century, coincident with episodes of repeated explosive volcanism centuries before the widely cited Maunder sunspot minimum (1645–1715 AD [Eddy, 1976]). Together with climate modeling and supported by other proxy climate reconstructions, our results suggest that repeated explosive volcanism at a time when Earth’s orbital configuration resulted in low summer insolation across the NH acted as a climate trigger, allowing Arctic Ocean sea ice to expand. Increased sea ice export may have engaged a self-sustaining sea-ice/ocean feedback unique to the northern North Atlantic region that maintained suppressed summer air temperatures for centuries after volcanic aerosols were removed from the atmosphere. “

  147. At Leif, “Our precisely dated records demonstrate…..”?

    What do they demonstrate? that a 20-year large ice cover increase peak from 1430 to 1450 was induced, according to the authors, by a volcano eruption occurred in their data in 1452 instead by the great solar Sporer minimum in 1420-1450 so evident in their own data?

    The data demonstrate the opposite of what these authors claim. The sun initiated the LIA in the late 13th century because of the Wolf solar Minimum and kept it alive for 4 centuries with alternate periods.

    Are you blind?

    See my own pictures, see the great correlation between temperature and solar reconstructions, for example

    http://www.friendsofscience.org/index.php?id=454

  148. Hate to interrupt the “discussion” but a couple of questions.

    If volcanism explains the LIA, shouldn’t it or its absence also be able to explain most of the climate of the last 2,000 year up to 1900? Shouldn’t its absence explain the MWP, for example, if the solar influence is not involved? Why shouldn’t the model be able to be extended?

    When I go to this page

    http://www.volcano.si.edu/world/largeeruptions.cfm

    I can’t see a whole lot of difference between the number of eruptions in the various time period of the last 2,000 years. I do notice, however, more eruptions are more recent which probably means the number and size of eruptions may be grossly inaccurate when we go back more than a few hundred years. How sure are we about the volcanism data?

    What does this do to the debate over whether the LIA was mainly Northern Hemisphere or worldwide? Shouldn’t the volcanic explanation settle the LIA as a worldwide phenonmenon?

  149. Leif, I think that it is you who are a little bit deluding yourself here.

    I try to repeat.
    What do they demonstrate? that a 20-year large ice cover increase peak from 1430 to 1450 was induced, according to the authors, by a volcano eruption occurred in their data in 1452 instead that by the great solar Sporer minimum in 1420-1450 so evident in their own data? Does it make sense?

    Why are you not capable to address the real scientific issue?

  150. Nicola Scafetta says:
    January 31, 2012 at 11:02 am
    that a 20-year large ice cover increase peak from 1430 to 1450 was induced, according to the authors, by a volcano eruption occurred in their data in 1452 instead that by the great solar Sporer minimum in 1420-1450 so evident in their own data? Does it make sense?
    The eruption in 1452 was not the cause of the LIA [which started a long time before], and they don’t claim that. The LIA [according to the paper] is a self-sustaining event over hundreds of years, helped along by the occasional eruption during the centuries.

  151. Nicola Scafetta says:
    January 31, 2012 at 10:12 am
    See my own pictures, see the great correlation between temperature and solar reconstructions, for example…
    Anybody who still uses the old Lean 2000 reconstruction automatically disqualifies himself from serious discussion.

  152. So if Greenland coastal ice expanded and weakened the Atlantics deep convective zones and caused colling why hasn’t it happened in the early 20th century when we know ice loss was large and why hasn’t happened again it the the last 30 years of supposed AGW.
    Thought climate scientists stated that Greenland and Arctic ice melt wouldn’t change the Gulf stream enough to off set AG…W now?? this study say’s different????

  153. Ok, so there are frozen plants under the glaciers.
    The glaciers grew in response to the little ice age caused by volcanoes.
    The little ice age was an aberration, so the glaciers extent “should” be where they were before the little ice age?
    Sounds like glacier retreat is just reversion to the norm.

  154. @ Leif
    “The eruption in 1452 was not the cause of the LIA [which started a long time before], and they don’t claim that. The LIA [according to the paper] is a self-sustaining event over hundreds of years, helped along by the occasional eruption during the centuries.”

    This theory, by excluding the Sun, is based on nothing and does not agree with the data. and mumerous other papers.

    They claim that the cooling periods are caused by volcano eruptions alone, and the sun does not matter, and consequently, for example, they are not able to explain the strong cooling in 1430-1450 with no significant volcano activity from 1350 to 1450 .

    About my works, I am not using Lean 2000 reconstruction alone, I am using a variery of solar reconstructions, including Lean 2005. Read better my papers, Leif!

  155. Nicola Scafetta says:
    January 31, 2012 at 2:25 pm
    This theory, by excluding the Sun, is based on nothing and does not agree with the data. and mumerous other papers.
    It is based on the data described by the authors and makes a lot of sense.

    I am using a variery of solar reconstructions, including Lean 2005. Read better my papers, Leif!
    Lean 2005 is not much better and you do use Lean 2000 as well, so as I said you are automatically disqualified.

  156. As I was listening to the CBC Radio 2 channel in my car this morning, the anchor mentioned this paper -Baffin Island is in Canada- and the author Miller was even interviewed!!! This is of course hardly coincidental: this paper is being promoted heavily.

    Leif quotes:
    “[16] Our precisely dated records demonstrate that the expansion of ice caps after Medieval times was initiated by an abrupt and persistent snowline depression late in the 13th Century, and amplified in the mid 15th Century, coincident with episodes of repeated explosive volcanism centuries before the widely cited Maunder sunspot minimum (1645–1715 AD [Eddy, 1976]).”

    Yet, NO geological data pertaining to these eruptions and their recurrence are offered. In fact their [12] does not even offer ONE reference supporting any of their assertions. Quite annoying when in fact this paragraph is the crux of their assumption! The subsequent Schneider etc… references are convenient model related stuff, hardly geological evidences. As shown in the Jiang et al. 2012 paper posted by Dave Wendt http://www.igsoc.org/journal/current/207/j11J138.pdf , one cannot say the period in question is exceptional regarding volcanism. Again, concomitance is not causation. That is precisely why the Miller paper is imo unsupported and pure conjecture. It only carefully describes the advance of ice cap on Baffin Island. Fine!
    Leif says: “The eruption in 1452 was not the cause of the LIA [which started a long time before], and they don’t claim that. The LIA [according to the paper] is a self-sustaining event over hundreds of years, helped along by the occasional eruption during the centuries.”
    So what’s the title of Miller’s paper for? It’s called “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks” is this not?

  157. Nicola Scafetta says:
    January 31, 2012 at 5:02 am

    Geoff, to better prove my point, may you prepare again the figure by adding the solar record depicted in Figure 2A too? Figure 2A, 2B and 2C should be together. You also need to add two red lines in concomitance of the two Ice cup peaks around 1275 and 1435, and show that they correspond to the two grand solar Wolf and Sporer solar minima exactly. Thank you.

    I think the TSI reconstruction used in the paper is a poor reference of solar activity. They should have used a direct isotope record in my opinion.

    I also call into question the accuracy of the “moss” records used in the paper used to calculate their PDF values. We have seen via the satellite ice records that every year can be different in spatial extent probably brought about by prevailing weather patterns.The data after 1452 is not convincing and simply assuming no more ice growth because of a permanent positive feedback mechanism caused by the 1452 explosion is not sufficient. Volcanic events have a very limited and short term affect on climate, but interesting how Leif will always jump on the wagon as it is all he has got in this area. More about agenda than science.

    Leif Svalgaard says:
    January 31, 2012 at 6:57 am

    Geoff Sharp says:
    January 31, 2012 at 2:33 am
    FUV penetrates down to a height of 30km (within the highest ozone band).
    —————————————–

    http://www.leif.org/research/Atmospheric-Structure.png

    That you would use that diagram as proof of FUV penetration is laughable. Once again your poor knowledge on this topic is exposed. I have found the following table provided by NASA to be mostly accurate. If you want to debate the deposition levels of FUV I have many papers and references that will back up the NASA table. Please spare us the boredom.

    http://www.nasa.gov/mission_pages/sdo/science/Solar%20Irradiance.html

  158. Nicola Scafetta says:
    January 31, 2012 at 2:25 pm
    they are not able to explain the strong cooling in 1430-1450
    Actually the strong cooling started around 1450…

    But you are missing the point of the paper, namely that the LIA was a self-sustained event that once started would run on for centuries [which it did].
    Personally, I don’t think the volcanoes are the whole answer, but just part of it. The sun, on the other hand, clearly has nothing to do with the LIA. It is even very likely that our indicator of solar activity is contaminated by climate, so the relationship goes the other way, see W. R. Webber et al. (A comparison of new calculations of the yearly 10Be production in the Earth’s polar atmosphere by cosmic rays with yearly 10Be measurements in multiple Greenland ice cores between 1939 and 1994—A troubling lack of concordance, manuscript in preparation, 2010) suggest that “more than 50% of the 10Be flux increase around, e.g., 1700 A.D., 1810 A.D. and 1895 A.D. is due to nonproduction related increases.” [read: deposition, i.e. climate] http://arxiv.org/ftp/arxiv/papers/1004/1004.2675.pdf

  159. Geoff Sharp says:
    January 31, 2012 at 3:24 pm
    If you want to debate the deposition levels of FUV I have many papers and references that will back up the NASA table. Please spare us the boredom.
    I think we have debated that enough. You have no real knowledge of this and hunt around until something that looks promising shows up. The primary absorber of FUV is molecular Oxygen above 100 km at 150 nm [and that is the part that varies up to 30%]. Very little just below 200 nm [which varies a lot less] penetrates deeper and has no effect. See e.g. Figure 1 of http://lpce.cnrs-orleans.fr/~ddwit/publications/UVproxies.pdf Note that there are three humps corresponding to different physical processes: The radiation in the MUV range (200–300 nm) mostly affects the stratospheric O3 concentration; the FUV range (122–200 nm) affects the upper mesospheric O2 excitation production and the lower thermospheric O2 dissociation; the EUV range (10–120 nm)
    affects the thermospheric O, O2 and N2 ionization and excitation productions.
    You have in the past tried to state that the EUV [and now the FUV] are the primary climate drivers. Simple physics demonstrates that they are not.

  160. TomRude says:
    January 31, 2012 at 3:14 pm
    So what’s the title of Miller’s paper for? It’s called “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks” is this not?
    They did not claim it started in 1450, but much earlier. People can make up their own minds about what they want to believe depending on their own biases.

  161. Geoff, Nick:

    The results of this image show that the variation in the sun has no correlation in the Ice Growth of the LIA.

    Do you agree with this assesment?

  162. Mitch Battros and others (Extinction Protocol) etc have done much to link solar flares to serious Earth Changes… that BIG orb in the sky surely must have some pull / influence on our planet otherwise it is simply taking up valuable space….. in space! :-)

  163. Volcanoes, even the biggest would only cool the planet for a few years at most , unless a deccan traps type event occurred during the little ice age that no one noticed.

    Solar cycles last much longer and as data indicates, (not models) a large grouping of low solar cycles occurred during this time and thus are a more likely a factor in the cooling of the planet at that time.

    Of course as we are now experiencing such a low cycle, we may all know the answer in years to come. This paper is just a cheap swipe from the warmists, they have to say that the sun, the big freaking ball of plasma 8 light minutes away has little effect on our planets thermal dynamics, that instead a bunch of mammals scratching around on the surface of this planet is controlling the thermostat for an entire planet.

  164. Eimear says:
    January 31, 2012 at 4:46 pm
    This paper is just a cheap swipe from the warmists, they have to say that the sun, the big freaking ball of plasma 8 light minutes away has little effect on our planets thermal dynamics
    Actually, the warmest promoters of the solar cause are the warmists, as that is the only thing in their mind that will explain the LIA and the MWP [apart from claiming there were no LIA and MWP]. You want to jump on their bandwagon?

  165. @ Leif,

    I think that you are not fair, as usual. As a solar scientist you should promote solar/climate interactions, you seem to hate the sun. There are a lot of paper showing the good correlation betwenen solar cycles and climate cycles. This paper is nothing.

    Volcano activity effect last only a few years at most. If it were true that a prolonged volcano effect would be so important we would measure it also during the last century. As I show in my paper, the volcano signals are strongly overestimated by the current models. Look at my figure

    The reasonable signature of the volcano signal (as prepared by other people, not me) are the blue and black curves, while the red curve is the typical GCM outputs.

    So, no way that the mechanisms proposed by this paper work.

    The volcanos give a contribution, but it is limited in time and duration.
    It is more likely that for some reason volcano activity is influenced by the changing of the climate induced by the sun, than viceversa.

    @ M.A.Vukcevic: nice record. There are better records, which are more clear that that.

    @ Geoff “I think the TSI reconstruction used in the paper is a poor reference of solar activity. ”

    Perhaps you are right, but when addressing the claim of an author there is the need of first look at the data theu use. These persons have done no attempt in estimating the solar effect on climate, so their attributions are not realistic.

  166. Leif Svalgaard says:
    January 31, 2012 at 4:02 pm

    The primary absorber of FUV is molecular Oxygen above 100 km at 150 nm [and that is the part that varies up to 30%]. Very little just below 200 nm [which varies a lot less] penetrates deeper and has no effect. See e.g. Figure 1 of http://lpce.cnrs-orleans.fr/~ddwit/publications/UVproxies.pdf Note that there are three humps corresponding to different physical processes

    Another example of your own references proving you wrong. Below is the diagram you reference with my annotations in red.

    You might need to research the Schumann-Runge bands (176-192.6nm) and their role in ozone production. The 2nd panel of the graph showing the % variation of this band, which is between10-20% (very significant).

    You might also like to research papers from Solomon and also Marsh and others who have shown for decades the importance of nitric oxide and molecular oxygen diffusion from the thermosphere and mesosphere to the stratosphere and the impacts on ozone production. The Lyman-alpha range (EUV) which can penetrate to 70km being critical in this process.

  167. Camburn says:
    January 31, 2012 at 4:28 pm

    Geoff, Nick:

    The results of this image show that the variation in the sun has no correlation in the Ice Growth of the LIA.

    Do you agree with this assesment?

    I agree the “PDF” data after 1452 looks suspicious. Before 1452 the data agrees with solar variation (isotope proxies) expectations on Ice Growth. The “PDF” data needs to be compared with other polar ice proxies if available.

    Tip. Beware of using text with the word landsch…dt included (the force that dare not mention its name). Your comment will go to the sin bin and then be moderated at a later date which usually disrupts the flow of conversation.

  168. Leif Svalgaard says:
    January 31, 2012 at 4:15 pm
    TomRude says:
    January 31, 2012 at 3:14 pm
    So what’s the title of Miller’s paper for? It’s called “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks” is this not?
    They did not claim it started in 1450, but much earlier. People can make up their own minds about what they want to believe depending on their own biases.
    ==
    Not at all! You put words -like this 1450 start- in my mouth. Either their title means what it says OR it is a smoke and mirror title made up to attract undue attention from the media -which it has considering how its author managed to get an interview extract broadcast on CBC Radio at noon- while pretending without proving. In any case, your return of serve was weak.

  169. “Putting these records together showed that cooling began fairly abruptly at some point between 1250 and 1300. Temperatures fell another notch between 1430 and 1455.”

    http://climaterealists.com/index.php?id=9040&linkbox=true&position=2

    1430’s
    “Majority of winters, [ perhaps 7 or 8 ] contained several weeks of widespread severe weather (NB: ‘weeks’, not the paltry ‘days’ we get end 20th / early 21st centuries.) According to Lamb, an experience not repeated / matched until the 1690’s, in the depth of the Little Ice Age (and certainly not in modern times).”

    http://booty.org.uk/booty.weather/climate/1400_1499.htm

    1430-1470 AD Ring Width < 0.035 mm (cold) LaMarche, 1978

    http://www.geo.arizona.edu/palynology/geos462/holobib.html

    So the 1430`s cooling cannot have been caused by 1452/3 the Kuwae eruption: http://en.wikipedia.org/wiki/Kuwae#Climatic_consequences_of_the_1452.E2.80.931453_event

  170. Leif Svalgaard says:
    January 31, 2012 at 12:01 am
    And BTW, the cosmic ray variation is not correct. The cosmic rays that reach the atmosphere vary foremost with the strength of the geomagnetic field rather than with solar activity. Here is the real cosmic ray variation: red curve at bottom: http://www.leif.org/research/INTCAL-Jasper.png and here for the past 10,000 years: http://www.leif.org/research/CosmicRays-GeoDipole.jpg The solar modulation are the small wiggles.

    ———————————————-
    The correlation would be a bit better for the last 700 years with your data, but earlier an offset and a different slope.

    However, Svensmark and Shaviv argue that the geomagnetic field only influences low energy rays and that these contribute only 3% to CR cloud formation. In that case, the solar activity should correlate better overall than the combined field and it does.

    I saw that similar issues had already been discussed at length in

    http://wattsupwiththat.com/2011/09/01/nir-shaviv-on-the-cloud-experiment-worth-a-read/

    I was surprised to see everyone focussing on high energy cosmic rays, and when I look Svensmark’s theory up by myself, it is about intermediate energy rays, as high energy are neither influenced by sun or earth, see figure 7 here:

    http://dahuang.dhxy.info/ClimateChange/j.1468-4004.2007.48118.x.pdf

    So, there is a high correlation of curves, multiple peaks and valleys at the same position (almost perfect after 1250) and a theory with a suggested mechanism.

  171. Nicola Scafetta says:
    January 30, 2012 at 3:33 pm
    The correlation between glacier/temperature changes with solar changes during the last 1000 year is well established. See for example

    ————————————————
    Leif marked his graph

    “200 yr filtered data”.

    Then the Austrian Speleothem is probably also 200 years filtered ?

    200 years are just 3 ocean oscillation cycles of 60-70 years. Filtering with a multiple of a full ocean cycle may be a good idea to remove ocean cycle “noise” and make the solar effect better visible.

  172. Geoff Sharp says:
    January 31, 2012 at 5:59 pm

    You might need to research the Schumann-Runge bands (176-192.6nm) and their role in ozone production. The 2nd panel of the graph showing the % variation of this band, which is between10-20% (very significant).

    You might also like to research papers from Solomon and also Marsh and others who have shown for decades the importance of nitric oxide and molecular oxygen diffusion from the thermosphere and mesosphere to the stratosphere and the impacts on ozone production. The Lyman-alpha range (EUV) which can penetrate to 70km being critical in this process.

    @Leif …The following paper by Hood encapsulates nearly every point and statistic that I have been trying to get across to you on this thread and previous threads re UV chemical forcing. It is a thorough document which includes all the big players in the atmospheric game. The paper shows how the different wave lengths of EUV and FUV modulate stratospheric ozone and in turn interact with planetary waves, zonal winds, the polar vortex and the AO index. The Lyman-alpha and Schumann-Rungs bands with their operating depths and influences are clearly outlined as I have shown, along with the importance of the species migration from above. All of your points are disputed.

    Take the time to read the whole document and bring yourself up to speed. If after reading in full, you still think solar chemical influences from highly varying UV are not responsible for climate changes in the troposphere, I am afraid there is no hope for you.

    ftp://ftp.lpl.arizona.edu/pub/lpl/lon/stratosphere/hood04agu.pdf

  173. Geoff Sharp says:
    January 31, 2012 at 5:59 pm
    You might need to research the Schumann-Runge bands (176-192.6nm) and their role in ozone production.
    The bands destroy ozone.
    the importance of nitric oxide and molecular oxygen diffusion from the thermosphere and mesosphere to the stratosphere
    The diffusion is exceedingly slow and does not contribute significantly [working against a density gradient of a factor of a thousand].

    TomRude says:
    January 31, 2012 at 6:35 pm
    Either their title means what it says
    Since the LIA started in the 13th century, the title has nothing to do with 1450.
    So the 1430`s cooling cannot have been caused by 1452/3 the Kuwae eruption
    Nobody says that, as the LIA started in the 13th century.
    Well actually on the graph it is warming for 50yrs from 1450.
    The deep dip was in the 1450s.

    Manfred says:
    January 31, 2012 at 8:22 pm
    However, Svensmark and Shaviv argue that the geomagnetic field only influences low energy rays and that these contribute only 3% to CR cloud formation. In that case, the solar activity should correlate better overall than the combined field and it does.
    Solar activity modulates the low energy rays. Above 10 GeV there is hardly any modulation. Svensmark does special pleading by claiming that the active rays has just high enough energy not to be modulated by the Earth, and just low enough energy to be modulated by the Sun.

  174. Nicola Scafetta says:
    January 31, 2012 at 5:37 pm
    As a solar scientist you should promote solar/climate interactions
    No, one must go where data and physics lead, not where wishful thinking and pseudo-science lure.

    you seem to hate the sun.
    I know the Sun.

  175. Geoff Sharp says:
    January 31, 2012 at 8:55 pm
    The following paper by Hood encapsulates nearly every point and statistic …
    The paper specifically excludes FUV and EUV [both being lower than 200 nm]:
    “Previously thought to produce only relatively minor changes in ozone concentration, radiative heating, and zonal circulation in the upper stratosphere, solar ultraviolet (UV) variations at wavelengths near 200 nm are increasingly recognized as a significant source of decadal variability throughout the stratosphere”.

  176. Geoff Sharp says:
    January 31, 2012 at 8:55 pm
    The following paper by Hood encapsulates nearly every point and statistic …
    You may want to be up to speed on this topic. Since Hood’s 2004 paper we have learned that the biggest solar cycle variation is not in EUV or FUV, but in MUV near 300 nm: slide 3 of http://lasp.colorado.edu/sorce/news/2011ScienceMeeting/docs/presentations/6b_Cahalan_Sedona_9-15-2011.pdf and being likely out of phase with the solar cycle.

  177. Leif Svalgaard says:
    January 31, 2012 at 8:56 pm

    Geoff Sharp says:
    January 31, 2012 at 5:59 pm
    You might need to research the Schumann-Runge bands (176-192.6nm) and their role in ozone production.
    ————————–
    The bands destroy ozone.

    Incredible. This is what Hood (and most of the scientific community) says.

    One mechanism by which solar variability may
    influence tropospheric climate involves changes in solar
    ultraviolet (UV) flux at wavelengths that affect ozone
    production and radiative heating in the stratosphere.
    Photodissociation of molecular oxygen (leading to ozone
    production) occurs in the Schumann-Runge bands and in the
    Herzberg continuum at wavelengths less than 242 nm (e.g.,
    Brasseur and Solomon [1984]). Radiation at these
    wavelengths (190 – 240 nm) can penetrate into the upper
    stratosphere (30 to 50 km; Herzberg [1965]) where the
    increased atmospheric number density results in the
    formation of the ozone layer.

    the importance of nitric oxide and molecular oxygen diffusion from the thermosphere and mesosphere to the stratosphere
    ————————
    The diffusion is exceedingly slow and does not contribute significantly [working against a density gradient of a factor of a thousand].

    Some references please?
    From:
    Mesosphere-to-stratosphere descent of odd nitrogen in
    February–March 2009 after sudden stratospheric warming
    S.-M. Salmi

    “High NOx amounts were transported from 80 to 55 km altitude in about 40 days”

    Read the Hood paper. You are grossly out of touch.

  178. Leif Svalgaard says:
    January 31, 2012 at 9:15 pm

    The paper specifically excludes FUV and EUV [both being lower than 200 nm]:

    Read the whole paper. He states 200nm because he has reliable data near that level. One excerpt:
    The penetration depth into the stratosphere of solar UV
    radiation is also a strong function of wavelength (e.g.,
    Herzberg [1965]). At the 121.5 nm solar Lyman α
    wavelength, the penetration altitude is approximately 70
    km. In the Schumann-Runge bands (~180 – 200 nm)
    radiation penetrates to an altitude range between about 40
    and 60 km. At 205 nm, the altitude of penetration
    approaches a minimum of 30 km
    . At wavelengths between
    205 nm and 300 nm, where solar spectral irradiance
    variability decreases gradually to zero, the altitude of
    penetration varies between 30 and 35 km. Thus, the
    maximum depth of penetration occurs near 205 nm where
    UV flux changes as large as 6% are observed on both the
    solar cycle and solar rotation time scales.

    Since Hood’s 2004 paper we have learned that the biggest solar cycle variation is not in EUV or FUV, but in MUV near 300 nm: slide 3 of

    Slide 3 shows nothing of the sort (output not irradiance is the key). The slide also incorrectly incorporates EUV (Lyman) in the FUV range. EUV has the largest variance over the solar cycle, this is recognized by all science, perhaps not in your universe tho.

  179. Well, at least they are admitting there WAS a Little Ice Age…

    FWIW, any article of the form “Our Computer Model Experiment Showed” ought to be seen as of the form:

    “Given these conclusions what assumptions can we draw”…

    OK, back at volcanoes and quakes: As Wilson (of Australia I think) has shown a change in Length Of Day correlation with solar cycles, it’s not hard to figure that changes in the rotation rate might set off some marginal volcanoes. Basically, I think the two come together when they come.

    IFF Volcanoes and solar shifts happen at the same time, BOTH will give the same correlation coefficients. Only the multiplication plug number in front of the equation need change.

    So model runs saying “Look! With our plug number FOO is 95% correlation coefficient! So Causal.” are just bad logic.

    WHY spin change with solar cycle is an interesting question. Could be anything from some kind of spin / orbit coupling to a solar current driven homopolar motor effect to a magnetosphere interaction to… But all these things tend to come together when they come too. So sorting out what is 90% causal and what is 5% causal and what is caused is going to be a bit hard. (And impossible via ‘computer simulations’…)

    At any rate, looking at a long term graph of temperatures and volcanoes shows the volcanoes cycle about the same time as climate cycles, and that is about in sync with various planetary motions.

    Thanks to Orbital Resonance, all sorts of bodies in space get into related ‘resonant’ motions. This means you can’t do correlation coefficients to find causality. The Moon, for example, is in an 179.x year period orbital shift pattern. The sun has a 179.y year cycle. Which is causal, which is correlation, which is coincidence, which is error band? “Good luck with that”…

    There are a bunch of lunar / tidal cycles that look to tie with climate cycles:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC18099/

    These same lunar tidal cycles have 1800 year nodes (that sit on top of some of the Bond Event dates) and even a 5000 ish year node. The faster nodes look to sit on top of the cycles of weather we see.

    So is it driven by tides? Perhaps changing how much cold water hits the Drake Passage? Or how much cold ocean water is stirred to the surface? Or perhaps the same tides set magma to wobbling and cause a few more volcanoes from time to time…

    Trying to disentangle things that are inherently tangled can be a bit of a fools errand…

    What matters far more to me is to realize that it may ALL be driven by the same metronome, and that CO2 is not part of the machine…

  180. Geoff Sharp says:
    January 31, 2012 at 10:21 pm
    The penetration depth into the stratosphere of solar UV radiation is also a strong function of wavelength
    That depth is not where most of the radiation ends up. It is like sunlight in the ocean, it may penetrate to a depth of 200 m, but it is extremely feeble at that depth. “only 73% of the surface light reaches a depth of 1 centimeter (less than a half inch)
    only 44.5% of the surface light reaches a depth of 1 meter (3.3 feet)
    22.2% of the surface light reaches a depth of 10 meters (33 feet)
    0.53% of the surface light reaches a depth of 100 meters (330 feet)
    0.0062% of the surface light reaches a depth of 200 meters
    Bottom line — most of the light is absorbed or scattered within the top few meters of the ocean.”
    Same thing with UV. A few photons may make it in very deep, most do not.

  181. E.M.Smith says:
    January 31, 2012 at 10:31 pm

    Thanks to Orbital Resonance, all sorts of bodies in space get into related ‘resonant’ motions. This means you can’t do correlation coefficients to find causality. The Moon, for example, is in an 179.x year period orbital shift pattern. The sun has a 179.y year cycle. Which is causal, which is correlation, which is coincidence, which is error band? “Good luck with that”…

    Hi Cheifo, I hate to be picky and off topic but I must point out that there is no 179 year period in relation to the solar system or Sun. The closest period is a rough 172 years. I give examples of this in a recent forum article that may provide some insight.

    http://tinyurl.com/2dg9u22/?q=node/226

  182. Geoff Sharp says:
    January 31, 2012 at 10:21 pm
    Slide 3 shows nothing of the sort (output not irradiance is the key). The slide also incorrectly incorporates EUV (Lyman) in the FUV range. EUV has the largest variance over the solar cycle, this is recognized by all science, perhaps not in your universe tho.
    Watt/m2 is the key, not silly percentage change. The FUV band definition differs a bit from field to field. A common definition is 100-200 nm, another one 120-200, but you can find still other ones out there, even 122-200 nm, straddling Lyman alpha.

  183. Leif Svalgaard says:
    January 31, 2012 at 8:56 pm
    (…) TomRude says:
    January 31, 2012 at 6:35 pm
    Either their title means what it says
    Since the LIA started in the 13th century, the title has nothing to do with 1450.
    So the 1430`s cooling cannot have been caused by 1452/3 the Kuwae eruption
    Nobody says that, as the LIA started in the 13th century.
    Well actually on the graph it is warming for 50yrs from 1450.
    The deep dip was in the 1450s.

    ==
    You are putting your own words (the 1450 date) in my mouth and then proudly debunk your own creation! Moreover you are also attributing comments to me that were not mine… Overload. EOM.

  184. TomRude says:
    January 31, 2012 at 11:16 pm
    You are putting your own words (the 1450 date) in my mouth
    this is what you said:
    “Leif says: “The eruption in 1452 was not the cause of the LIA [which started a long time before], and they don’t claim that. The LIA [according to the paper] is a self-sustaining event over hundreds of years, helped along by the occasional eruption during the centuries.”
    So what’s the title of Miller’s paper for? It’s called “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks” is this not?”

    I grant that it is a bit obscure, but one interpretation is that your “so what’s the title of Miller’s paper for?” was a sort of rebuttal of what I said [the 'so' connecting the two statements], i.e. that you think that 1452 was the cause etc. It is possible that that interpretation is not what you meant, in which case I’m at a loss as what you meant.

  185. Leif Svalgaard says:
    January 31, 2012 at 11:02 pm

    Watt/m2 is the key, not silly percentage change. The FUV band definition differs a bit from field to field. A common definition is 100-200 nm, another one 120-200, but you can find still other ones out there, even 122-200 nm, straddling Lyman alpha.

    There is some fluctuation in the scale boundaries, especially if reading older material. But most these days refer to the Lyman-alpha portion (125.6nm) as the top end of the EUV scale with 10 being the baseline and XUV below 10. This is certainly the scale that NASA has adopted.

    The primary function you are deliberately hiding from is that different parts of the UV spectrum are absorbed at different levels of the atmosphere. Each layer of the spectrum performs a different function that is responsible for the total package. EUV and FUV are major players and if there are changes in the output of these parts of the spectrum, there are downstream changes that affect the mesosphere,stratosphere AND troposphere. You can resist the accepted science, but it only makes you look silly.

  186. Geoff Sharp says:
    January 31, 2012 at 10:59 pm

    Hi Cheifo, I hate to be picky and off topic but I must point out that there is no 179 year period in relation to the solar system or Sun. The closest period is a rough 172 years. I give examples of this in a recent forum article that may provide some insight.

    Well, I was just paraphrasing that article:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC18099/

    [A cause for such greater regularity in tidal forcing might be resonances of other bodies of the solar system, especially the outer planets. We are struck by the close correspondence of the average period of the 180-year tidal cycle of 179.5 years (1/10 of that of the 1,800-year cycle) and the period of the sun's rotation about the center of mass of the solar system of 179.2 years, the latter a manifestation of planetary resonances (13).]

    So you can be “pickey” at them.. ;-) . Me? Frankly, I can’t keep track of all the various ‘cycles’ folks seem to find… There seems to be about a hundred just for the sun ;-)

    Add in ‘average smearing’ and you get things like Bond Events with an average of 1470, but it has two nodes at 13xx and 1800 (and the average in the middle – kind of like sunspot cycles with an average of 11 years that it tends to avoid actually having ;-)

  187. Ultimately to make the case the LIA was caused by volcanic activity it seems you need to be able to show that volcanic activity before and during it was significantly higher than activity either before or after it.

    From what I have read, there is no evidence at all to support this.

    Just cherry picking some eruptions and running them through a model really isn’t evidence at all.

  188. If cosmic changes affect the atmosphere, it’s likely they affect magma.

    Cosmic rays ionize molecules in the atmsphere. Why not magma?

    With both changes to fluid and magnetic field, I’d think there would be changes to pressures and circulation paterns in fluids.

  189. Leif Svalgaard says:
    January 31, 2012 at 11:34 pm
    TomRude says:
    January 31, 2012 at 11:16 pm
    You are putting your own words (the 1450 date) in my mouth
    this is what you said:(..)
    ===
    Leif here is YOUR original post:
    Leif Svalgaard says:
    January 31, 2012 at 11:14 am
    Nicola Scafetta says:
    January 31, 2012 at 11:02 am
    that a 20-year large ice cover increase peak from 1430 to 1450 was induced, according to the authors, by a volcano eruption occurred in their data in 1452 instead that by the great solar Sporer minimum in 1420-1450 so evident in their own data? Does it make sense?

    The eruption in 1452 was not the cause of the LIA [which started a long time before], and they don’t claim that. The LIA [according to the paper] is a self-sustaining event over hundreds of years, helped along by the occasional eruption during the centuries.

    ==
    You wrote this not me. EOM

  190. Geoff Sharp says:
    January 31, 2012 at 11:58 pm
    But most these days refer to the Lyman-alpha portion (125.6nm) as the top end of the EUV scale with 10 being the baseline and XUV below 10. This is certainly the scale that NASA has adopted.
    NASA don’t ‘adopt’ things. Individual scientists write that stuff, e.g. [ http://www.archive.org/details/nasa_techdoc_19970004842 ] “We observed the Io torus from 820-1140 A on universal time (UT) 20.25 July 1994 from a sounding rocket telescope/spectrograph. These observations serve as only the fourth published spectrum of the torus in this wavelength range, and the only far ultraviolet (FUV) data documenting the state of the torus during the Shoemaker Levy 9 Impacts.” saying that 82-114 nm is FUV. Just don’t claim that someone is ‘wrong’ on this just because they prefer a different boundary.

    EUV and FUV are major players and if there are changes in the output of these parts of the spectrum, there are downstream changes that affect the mesosphere,stratosphere AND troposphere. You can resist the accepted science, but it only makes you look silly.
    The energy in EUV and FUV is too minute to have any significant effects on the troposphere and no climate effects have been demonstrated. ‘Accepted science’ has to do with effects in the thermosphere and upper mesosphere. There is no ‘accepted science’ that EUV and FUV are major players in climate.
    BTW, FUV during the 20th century was the same as FUV in the 18th century. Perhaps you are also claiming that the climate was the same, firmly adhering to the AGW view that there was no LIA at all.

    Edim says:
    February 1, 2012 at 4:21 am
    Those who know know that they don’t know. And vice versa.
    arguing from a position of ignorance does not seem very fruitful, but suit yourself.

    TomRude says:
    February 1, 2012 at 9:29 am
    So what’s the title of Miller’s paper for? It’s called “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks” is this not?”
    Provided you will acknowledge that you wrote the above, could you please parse it and explain what it means.

  191. Leif Svalgaard says:
    February 1, 2012 at 10:00 am

    The energy in EUV and FUV is too minute to have any significant effects on the troposphere and no climate effects have been demonstrated. ‘Accepted science’ has to do with effects in the thermosphere and upper mesosphere. There is no ‘accepted science’ that EUV and FUV are major players in climate.

    We are not talking about energy as you well know…we are talking chemical changes that affect ozone etc.

    I have referenced Hood, Solomon, Marsh, Baldwin and many other authors who are considered experts in this field. They all disagree with Dr. Svalgaard, who has no expertize in this area. I rest my case.

  192. Geoff Sharp says:
    January 31, 2012 at 11:58 pm
    EUV and FUV are major players and if there are changes in the output of these parts of the spectrum, there are downstream changes that affect the mesosphere,stratosphere AND troposphere. You can resist the accepted science, but it only makes you look silly.

    This is what ‘accepted science’ says:
    Solar Output Signals in Troposphere:
    Visible/IR: small “bottom up” signals in reported in troposphere
    UV: clear heating effects in stratosphere (ozone layer) – may have subtle “top down” effects on troposphere
    EUV: dominates thermosphere, no evidence nor credible mechanism for coupling to the troposphere
    X-Rays: major effects in thermosphere, no evidence or credible mechanism for coupling to the troposphere
    Solar wind: same as for EUV and X-rays
    Cosmic Rays: proposed modulation of cloud cover
    SEPs: destroy ozone so may have similar effects to UV
    Slide 8 of http://www.rmets.org/pdf/presentation/20111207-lockwood.pdf

    As you say: resisting accepted science only makes you look silly.

  193. Geoff Sharp says:
    February 1, 2012 at 2:13 pm
    We are not talking about energy as you well know…we are talking chemical changes that affect ozone etc. [...] I rest my case.
    The chemical changes have very little influence on the ozone layer and no known or accepted climate effects. You misread and misinterpret your references. But it is time anyway to rest your sorry ‘case’.

  194. Geoff Sharp says:
    January 31, 2012 at 11:58 pm
    You can resist the accepted science
    From http://www.nature.com/nature/journal/v467/n7316/full/nature09426.html
    “our findings raise the possibility that the effects of solar variability on temperature throughout the atmosphere may be contrary to current expectations”
    The reason for this is the recent finding that “using the SIM data, solar radiative forcing of surface climate is out of phase with solar activity” due to the unexpected large variation in middle ultraviolet [not FUV or below]. Time for you to get up to speed on this…

  195. E.M.Smith says:
    January 31, 2012 at 10:31 pm

    ================

    That is the best point made in this discussion and I fully agree.

  196. Leif Svalgaard says:
    February 1, 2012 at 2:46 pm

    Keep trying Leif, your references are weak. Lockwood is certainly no expert.

    REPLY: IMHO he’s more of an expert than you are Geoff. Take a time out from WUWT for a couple of days, I don’t want another one of your fights breaking out. – Anthony

  197. Jon says:
    February 1, 2012 at 10:44 am

    This paper is mostly discredited here by a volcanologist: http://www.wired.com/wiredscience/2012/01/volcanoes-and-the-little-ice-age-not-the-smoking-gun/#more-94336

    Some interesting extra facts presented in this link. Miller has used the global or southern hemisphere SO2 record in his study, but when looking at the northern hemisphere the profile looks very different, esp around 1452. If the NH ice core records didn’t see the 1452 eruption, how was the northern ice sheet affected according to Miller’s theory?

  198. Geoff Sharp says:
    February 1, 2012 at 6:56 pm

    REPLY: IMHO he’s more of an expert than you are Geoff. Take a time out from WUWT for a couple of days, I don’t want another one of your fights breaking out. – Anthony

    I am not saying I am an expert. I have been posting peer reviewed papers from the top atmospheric authors that cover decades of research. Lockwood is not renown for his work in atmospheric science. I am happy to take a couples of days break, but I feel you are playing the censor.

    REPLY: Last time when you got fiery feisty, you ended up with a couple of months ban. I’m seeing the same pattern beginning to emerge again. I’m suggesting you take a break so I don’t HAVE to play censor – Anthony

  199. Geoff Sharp says:
    February 1, 2012 at 7:18 pm
    I have been posting peer reviewed papers from the top atmospheric authors that cover decades of research. Lockwood is not renown for his work in atmospheric science.
    One does not need to be renowned, only to know the science, and he is just [as I] reporting on ‘accepted science’ in a talk given at the Royal Meteorological Society. The papers you refer to are alright as they go, but are irrelevant for lower atmospheric physics and neither the energy deposited nor the chemical changes in the upper atmosphere are large enough to materially affect the lower. In the next talk at that meeting, Joanna Haigh [who is renowned] confirms that http://www.rmets.org/events/abstract.php?ID=4649

  200. “neither the energy deposited nor the chemical changes in the upper atmosphere are large enough to materially affect the lower”

    Any change in the stratospheric temperature will affect the height of the tropopause such that if the gradient between equator and pole is affected then the surface air pressure distribution including the permanent climate zones will slide poleward or equatorward beneath the tropopause.

    Hence the significance of this:

    “our findings raise the possibility that the effects of solar variability on temperature throughout the atmosphere may be contrary to current expectations”.

    I have previously analysed one of the possibilities in some detail here:

    http://climaterealists.com/index.php?id=6645

    “How The Sun Could Control Earth’s Temperature”

    Is there a killer point in the current ongoing research that suggests an alternative scenario ?

  201. Re: Jon

    I took a look at the paper you referenced and found it basically making much the same point I have been making and even references one of the same websites. Thanks.

    In the midst of this side argument about solar influence, I think key points have missed about the fundamental flaws in this paper.

    For one thing, the LIA is, according to Wikipedia, occurred from 1550 to 1850 and this paper is discussing events occurring up to almost 300 years before that as triggering sea-ice changes that were sustained by further eruptions. Aside from dramatically changing the time frame of the LIA and expanding it by about 300 years, there is no evidence of an ongoing level of eruptions throughout the entire period to sustain the changes or any diminution of eruptions to cause the changes to stop. As a matter of fact, the 19th century was extremely active in terms of volcanic eruptions which is period when the LIA ends. That a strong eruption can cool the Earth for a number of years isn’t a question, but whether it can set in motion a self-sustaining cooling trend without additional more or less equivalent eruptions (which clearly didn’t happen) is mostly conjecture. Also needing clarification is how warm periods could occur during this self-sustaining trend.

  202. Stephen Wilde says:
    February 2, 2012 at 4:08 am
    Any change in the stratospheric temperature will affect the height of the tropopause such that if the gradient between equator and pole is affected then the surface air pressure distribution including the permanent climate zones will slide poleward or equatorward beneath the tropopause.
    Any large enough change will affect …
    This is the key. Clearly a change of 0.00000001K will not affect anything measurably. So your word ‘any’ has to be suitable quantified.

  203. Leif Svalgaard said:

    “Any large enough change will affect …
    This is the key. Clearly a change of 0.00000001K will not affect anything measurably. So your word ‘any’ has to be suitably quantified.”

    It seems large enough to many. Your quantification is way out when chemically induced changes in ozone amounts at different levels are taken into account.

    The very papers that you link to concede larger changes than that and that there is a top down effect and that in some layers of the atmosphere (above 45km) the sign of the solar effect is the opposite of that expected from established science.

    My suggestion is the only one that seeks to account for that reverse sign effect. In fact my article was written before that reverse sign effect was actually publicised. I felt obliged to assume that the reverse sign effect existed because of other real world observations.

  204. Some of what I see from the claims in the paper:

    (1). M. Mann is aware that there was in fact a little ice age.

    (2). Ice receeding as of ‘today’ shows that there was none in the past as evidenced by plant growth now being revealed under the ice.

    (3). The title of the paper is deceptive with regards to its content.

    (4). Climate can change abruptly without the forcing of manmade CO2.

    (5). The effect of a forcing event can last for a long time. Is the Earth still recovering from the little ice age?

    There are a lot of solid arguments presented contrary to claims made in the paper and contrary to the title of the paper.

    So what does all this mean? Probably nothing important.

  205. I have been saying for some time that solar variability affects the vertical temperature profile of the atmosphere so as to alter the gradient in the height of the tropopause between equator and pole.

    That allows the permanent climate zones to shift poleward or equatorward as part of a global energy balancing exercise.It is the relative tropopause heights at equator and poles that matter. Generally the oceans most affect the heights at the equator and the sun affects most the heights at the poles and each effect can suppement or offset the other at an given time.

    It is a pair of see saws, one in each hemisphere, with the tropopause as the cross piece and the fulcrum around 45 degrees north and south though that position is affected by sea and landmass distribution such that the climate system is slightly unbalanced leading to a tendency for the Arctic to warm when the Antarctic is cooling and vice versa.

    The papers at the RMS talk that Leif has referred to are generally supportive of that proposition though as far as I can see none of the contributors has drawn it all together to arrive at that conclusion.

    The reason for such shifting of the climate zones is to maintain as far as possible the baseline adiabatic lapse rate as set by atmospheric pressure and solar irradiation. Anything that seeks to disturb that lapse rate is automatically offset by a change in the rate of energy flow from surface to space INSTEAD of any change in system energy content.

    I have been saying for years that what we see as climate change is simply a redistribution of surface energy as the rate of flow from surface to space changes over time.

    The manifestation of that process is poleward and equatorward climate zone shifting which gives the largest regional effects in the middle latitudes.

    It is likely that every planet with an atmosphere does much the same thing which is why it has been observed that for both Venus and Earth the atmospheric temperature at a given pressure is the same subject only to an adjustment for the distance of each planet from the sun.

    In so far as GHGs have any effect it is simply negated by a miniscule such shift as compared to the large shifts from solar and oceanic causation.

    Similar effects occur as a result of volcanic outbreaks.

    As far as I can tell my proposals are consistent with all the papers in that RMS talk.

  206. Stephen Wilde says:
    February 2, 2012 at 9:02 am
    As far as I can tell my proposals are consistent with all the papers in that RMS talk.
    As long as the proposals are not quantitative [giving numbers] no such claim can really be made.

  207. “As long as the proposals are not quantitative [giving numbers] no such claim can really be made”

    As I’ve pointed out before, there are lots of phenomena that could invalidate my proposals.

    For example:

    i) If the ozone quantities in the region above 45km had NOT increased at a time of quiet sun.

    ii) If the stratosphere were STILL cooling at the pre 1995 rate.

    iii) If the polar air masses were NOT surging across the middle latitudes more often.

    iv) If temperatures had NOT stopped rising around 1998.

    v) If the record negative AO had NOT coincided pretty neatly with the low solar minimum between cycles 23 and 24.

    and lots more are possible.

    So, quantification isn’t necessary if the direction of trend is used as a diagnostic indicator.

  208. Stephen Wilde says:
    February 2, 2012 at 12:22 pm
    So, quantification isn’t necessary if the direction of trend is used as a diagnostic indicator.
    Your bar is a lot lower than mine. For example: “i) If the ozone quantities in the region above 45km had NOT increased at a time of quiet sun.” What time precisely [year, months]? Not increased by how much? including error bars, and so on.

  209. “i) If the ozone quantities in the region above 45km had NOT increased at a time of quiet sun.” What time precisely [year, months]? Not increased by how much? including error bars, and so on.”

    See Joanna Haigh’s papers for the period 2004 to 2007 and possibly subsequently.

    I know you are aware of them.

  210. Stephen Wilde says:
    February 2, 2012 at 1:44 pm
    See Joanna Haigh’s papers for the period 2004 to 2007 and possibly subsequently.
    Not good enough as she does not give any estimates of how well her results match your theory. Again, without numbers you have nothing.

  211. Stephen Wilde says:
    February 2, 2012 at 9:02 am

    Thanks Stephen.

    The papers at the RMS talk that Leif has referred to are generally supportive of that proposition though as far as I can see none of the contributors has drawn it all together to arrive at that conclusion.

    The Haigh presentation that Leif referenced is all about solar effects on Earth’s climate. Many references to varying ozone production , planetary waves and jet stream changes as a result. Of note she also clearly displays that EUV and FUV are the prime part of the spectrum used in ozone production

    Haigh, Hood and Baldwin are also pushing in the same direction, ozone changes from UV modulation at solar min, affect atmospheric weather patterns.

  212. Geoff Sharp says:
    February 3, 2012 at 10:51 pm
    Of note she also clearly displays that EUV and FUV are the prime part of the spectrum used in ozone production
    In the mesosphere at 90 km altitude, where the ozone produced is less than 1/10,000 of that in the stratosphere and therefore has no measurable effects on climate.

  213. Well, Leif. I think you are struggling.

    All I need is a cooling temperature trend in mesosphere and stratosphere when the sun is active and a warming trend in those layers when the sun is less active.

    That is enough to alter the gradient of the tropopause heights between equator and pole so as to allow the climate zones to slide poleward or equatorward just as actually observed.

    The observations as to ozone quantity trends in the mesosphere (above 45km) point to that very effect.

    All that is required is to alter the fine balance between ozone creation and ozone destruction to achieve a change in temperature trend. Thae absolute quantities of ozone are of little relevance.

    Proof and precise quantification will have to await better sensing devices.

  214. Leif Svalgaard says:
    February 3, 2012 at 11:09 pm

    In the mesosphere at 90 km altitude, where the ozone produced is less than 1/10,000 of that in the stratosphere and therefore has no measurable effects on climate.

    All wrong. The components of ozone are built at higher altitudes, the shorter wave lengths in the spectrum necessary for the production of species required to build ozone as well as destroy. Ozone that is measured at 35km is mostly a product of the system above. Any UV radiation (MUV) that manages to penetrate the lower stratosphere is mainly absorbed by the ozone created from above. MUV is between 200-300nm, photodissociation that builds ozone can only happen under 240nm.

    Haigh clearly shows this in the diagrams I referenced. Do you have evidence suggesting Haigh is wrong?

  215. Stephen Wilde says:
    February 4, 2012 at 3:26 am
    All I need is a cooling temperature trend in mesosphere and stratosphere when the sun is active and a warming trend in those layers when the sun is less active.
    So you need the same trends in both mesosphere and stratosphere. The observations show that the trends are opposite, e.g. Figure 3 of http://www.leif.org/EOS/2011GL047561.pdf

  216. The ozone trends are opposite but the temperature trends are the same.

    Both layers cooled when the sun was more active and now that the sun is less active both layers seem to be moving towards a warming trend. Cwertainly the cooling of the stratosphere has stopped.

    That tells us that the mesospheric trend dominates both layers.

    When the sun is active the cooling effect of less ozone in the mesosphere causes the stratosphere to cool as well despite more ozone below 45km.

  217. Stephen Wilde says:
    February 4, 2012 at 11:49 am
    Both layers cooled when the sun was more active and now that the sun is less active both layers seem to be moving towards a warming trend.
    That statement shows that without numbers you just hand wave. Figure 3 shows that from 2002 to 2008 ozone increased in the mesosphere and decreased in the stratosphere as solar activity went from more active [SSN=100] to less active [SSN=5] and that from 2009 to 2011 ozone decreased in the mesosphere and increased in the stratosphere as solar activity went from less active [SSN=5] to more active [SSN=50].

  218. Leif,

    That just confirms what I said, that the ozone trends are opposite in each layer. It seems that even applies during the course of a single solar cycle on the basis of the figures you provide.

    However you well know that my focus is on multiple cycles on a timescale up to that of MWP to LIA to date.

    On that timescale individual cycles are of little relevance and the trends showed a cooling of both layers when the sun was more active across multiple cycles and no such cooling, possibly a little warming now that the sun is less active. The slight wobble during a single cycle does not detract from the longer term pattern.

  219. Hi Leif: good to find you commenting here as I’d got a bit concerned that your solar data didn’t seem to have been updated on your website for a while.

    What is the latest? any advance on 50?

  220. “The standard explanation of long-term ozone trends is the changing amount of CO2,”

    It is the long term stratospheric temperature trend that you are referring to isn’t it?

    But it broke down from the mid 90s to date because the stratosphere stopped cooling despite increasing CO2.

  221. Stephen Wilde says:
    February 5, 2012 at 9:34 am
    But it broke down from the mid 90s to date because the stratosphere stopped cooling despite increasing CO2.
    Because the cloroflourocarbon effects are diminishing. Check Lean’s slide again.

  222. “Because the cloroflourocarbon effects are diminishing. Check Lean’s slide again”

    Actually because the sun is less active,ozone is increasing above 45km thus warming the mesosphere and the stratosphere is following the mesosphere temperature trend.

    I don’t accept that CFcs or CO2 were ever a significant factor.

  223. Stephen Wilde says:
    February 5, 2012 at 10:04 am
    I don’t accept that CFcs or CO2 were ever a significant factor.
    Well, that automatically disqualifies you from consideration, because you let your personal bias stand in the way of the science. Your loss.

  224. Geoff Sharp says:
    February 4, 2012 at 6:12 am
    Do you have evidence suggesting Haigh is wrong?
    Why not ask her:

    From: Leif Svalgaard [mailto:lsvalgaard@gmail.com]
    Sent: 04 February 2012 08:12
    To: Haigh, Joanna D
    Subject: climate effect of EUV and FUV

    Dear Joanna,
    In your various papers, e.g. your talk at the recent RMS meeting you discuss the effect of varying UV on the climate, but do not seem to consider EUV and FUV. What is the reason for this? as EUV and FUV exhibit a larger solar cycle effect.

    On Sun, Feb 5, 2012 at 10:08 AM, Haigh, Joanna D wrote:
    Hello Leif
    Of course you are correct that variations in EUV and FUV have a large effect on the upper atmosphere but there is little evidence that they have any influence on the lower stratosphere or the troposphere which are the focus of my research.
    Best wishes,
    Joanna

    —–

    With your reverence for ‘accepted’ science from renowned authors this should settle the matter for you.

  225. No personal bias. Simply an observation that a cooling stratosphere is required for poleward shifting jets so if CFCs or CO2 were responsible then the jets would not now be diving further equatorward.

    Whatever ‘improvement’ might have arisen from CFC reductions would have been offset by the continuing increases in CO2 such that the observed change in atmospheric behaviour since around 2000 should not have happened.

    Furthermore those changes that have occurred match nicely with the changes in jet stream behaviour between MWP to LIA and LIA to date long before human CFCs and CO2 were ever an issue.

    So I have plenty of empirical evidence supporting my assessment.

  226. Stephen Wilde says:
    February 5, 2012 at 10:46 am
    Whatever ‘improvement’ might have arisen from CFC reductions would have been offset by the continuing increases in CO2 such that the observed change in atmospheric behaviour since around 2000 should not have happened.
    Study slide 25 again. The modern data fits the CFC CO2 changes quite well.

  227. Stephen Wilde says:
    February 5, 2012 at 10:46 am
    Simply an observation that a cooling stratosphere is required for poleward shifting jets
    not at all, the jets are determined by horizontal temperatures, i.e. the difference between the equator and the poles. e.g. in the winter the polar jet moves south and becomes stronger because the North Pole gets colder but the equator stays about the same temperature. This increases the temperature contrast and moves the strengthened polar front jet farther south.

  228. “not at all, the jets are determined by horizontal temperatures, ”

    There is such a bottom up seasonal effect but it is not the whole story.

    The jets are also affected beyond normal seasonal variation such as between MWP and LIA and LIA to date by longer term changes in the gradient of the height of the tropopause between equator and pole.

    On those timescales the jets can be shifted by changes in the temperature of the stratosphere above the poles relative to that above the equator. A warmer stratosphere above the poles relative to above the equator alters the gradient of the tropopause height to push the jets equatorward and a cooler stratosphere above the poles relative to above the equator alters that gradient to draw the jets back poleward. A warmer stratosphere lowers the tropopause height and a cooler stratosphere raises it.

    Recent evidence suggests that such solar induced movements can occur on much shorter timescales too, especially since the recent record solar minimum gave a record negative AO and the recent solar change towards the solar maximimum of cycle 24 has shown a somewhat more positive AO.

    Rather than continuing to criticise here I suggest that you (and I) just continue to observe developments. That will resolve the issue one way or the other but since I first proposed such a mechanism some years ago the ongoing evidence is generally supportive.

    After all, it would be quite a coincidence for the record negative AO to occur at just the time of such a low solar minimum merely by chance given that my proposals anticipated just such an event.

    We can but wait and see whether a correlation continues to hold.

  229. Stephen Wilde says:
    February 5, 2012 at 12:15 pm
    Recent evidence suggests that such solar induced movements can occur on much shorter timescales too, especially since the recent record solar minimum gave a record negative AO and the recent solar change towards the solar maximimum of cycle 24 has shown a somewhat more positive AO.
    Just before you were saying that your effects were on time scales of centuries, now you are down to single years.

  230. Stephen Wilde says:
    February 5, 2012 at 12:15 pm
    Rather than continuing to criticise here I suggest that you (and I) just continue to observe developments.
    Rather than continue to hand wave here, I suggest you just continue to observe and some decades down the road come back with your realization.

  231. Leif Svalgaard says:
    February 5, 2012 at 10:40 am

    On Sun, Feb 5, 2012 at 10:08 AM, Haigh, Joanna D wrote:
    Hello Leif
    Of course you are correct that variations in EUV and FUV have a large effect on the upper atmosphere but there is little evidence that they have any influence on the lower stratosphere or the troposphere which are the focus of my research.
    Best wishes,
    Joanna

    —–

    With your reverence for ‘accepted’ science from renowned authors this should settle the matter for you.

    Joanna is only stating the obvious because, EUV and FUV have already done their work at higher altitudes. Why dont you sent her another email and ask her if EUV and FUV are involved in ozone creation and modulation. We both know her answer will be inline with the diagrams she references.

  232. Geoff Sharp says:
    February 5, 2012 at 5:48 pm
    Why dont you sent her another email and ask her if EUV and FUV are involved in ozone creation and modulation. We both know her answer will be inline with the diagrams she references.
    As I have said so often, EUV and FUV do their thing, but so high up and in such thin air that it has no influence on the climate below, as Joanna confirms: “there is little evidence that they have any influence on the lower stratosphere or the troposphere”.

  233. Leif Svalgaard says:
    February 5, 2012 at 7:42 pm

    As I have said so often, EUV and FUV do their thing, but so high up and in such thin air that it has no influence on the climate below, as Joanna confirms: “there is little evidence that they have any influence on the lower stratosphere or the troposphere”.

    She is talking about in situ influence at lower levels. Send another email and ask the correct question, if not I can do. Also the primary area of interest is the upper stratosphere and lower mesosphere, ozone fluctuations at these levels are thought to affect the polar vortex. This inturn has an indirect effect on the troposhere, like we see in Europe right now with a neg AO and bitter Arctic winds from the jet stream..

  234. “Just before you were saying that your effects were on time scales of centuries, now you are down to single years.”

    Just so. The influence over centuries are clear to me and various others.

    The recent short term correlations have been surprising to me hence my suggestion that we keep an eye on them.

  235. Geoff Sharp says:
    February 5, 2012 at 9:49 pm
    Also the primary area of interest is the upper stratosphere and lower mesosphere, ozone fluctuations at these levels are thought to affect the polar vortex.
    The issue was if EUV is a key climate driver, and her answer [and accepted science] was that it is not.

  236. Leif Svalgaard says:
    February 6, 2012 at 5:16 am

    Geoff Sharp says:
    February 5, 2012 at 9:49 pm
    Also the primary area of interest is the upper stratosphere and lower mesosphere, ozone fluctuations at these levels are thought to affect the polar vortex.
    —————————————
    The issue was if EUV is a key climate driver, and her answer [and accepted science] was that it is not.

    EUV and FUV is the issue, both with their high solar cycle variance are important if you wish to understand the solar/climate connection.

    I am currently in conversation with Joanna and she has confirmed my previous statements. When the question is asked correctly, her answer along with decades of atmospheric research shows clearly that EUV and FUV are the major controllers of ozone in the upper stratosphere and lower mesosphere.

    My question to Joanna:

    “I am mainly concerned with the area 50-70km above the surface, this seems to be the area that Baldwin and others suggest is crucial for determining northern polar vortex disruption. I think it is clear that FUV is a major player in the photodissociation process in the 50-70km region (please correct me if I am wrong) that determines ozone quantities in this range. Outside of photodissociation the downwelling of nitric oxide produced in the thermosphere by EUV and EPP as shown by Salmi et al must have an effect on total ozone in the 50-70km region (even if isolated to polar regions). So am I wrong in suggesting that EUV and FUV are responsible to a large extent for the ozone modulation and production in the 50-70km region?”

    Joanna’s response:

    Not wrong in that. But we were talking about lower atmosphere.
    Energetic particles influence ozone, especially in the winter polar mesosphere but you still have to work out how the influence may get lower.One issue to consider: higher solar activity means more UV means more ozone but higher solar activity also means more particle events so more NOx leading to ozone destruction.

    Joanna was more interested in the lower levels of the atmosphere, but the important level is 50-70km. Baldwin and Hood have the mechanism to influence the troposphere.

    So I would suggest you are very wrong (again) about so called “accepted science”.

  237. Geoff Sharp says:
    February 9, 2012 at 4:31 am
    her answer along with decades of atmospheric research shows clearly that EUV and FUV are the major controllers of ozone in the upper stratosphere and lower mesosphere.
    Upper mesosphere at 90 km would be more correct.

    So I would suggest you are very wrong (again) about so called “accepted science”.
    What Joanna actually said was:
    “Photodissociation of molecular oxygen takes place through the Schumann-Runge Continuum (130-175nm), the Schumann-Runge Bands (175-200nm) and the Herzberg Continuum (200-242nm). While some radiation at wavelengths less than 200nm does penetrate to these levels the actual number of photons is relatively very small so it is the wavelengths greater than 200nm that are dominant. The plot below shows heating rates – indicative of the rate of absorption of solar energy – showing contributions of Schumann-Runge Continuum, Bands, Herzberg and also absorption by ozone in the Hartley, Huggins and Chappuis bands. The S-R components are tiny below about 70 km (note log scale). [I have included this plot because I had it easily available. What you actually need is photodissociation rates rather than heating rates – to look at photon numbers rather than energies – but in that case the relative proportions at shorter wavelengths would be even smaller].”

    She also said that there was little evidence that EUV and FUV had any influence on the climate, which was the issue at hand.

  238. Leif Svalgaard says:
    February 9, 2012 at 6:55 am

    Upper mesosphere at 90 km would be more correct.

    My question was framed very specifically with the 50-70km zone outlined. I also have included NOx reactions which you conveniently leave out.

    What Joanna actually said was:

    You left out some important parts, she was discussing absorption rates at 50km.

    “Peak ozone production occurs near 50km altitude where there is a balance between the production of atomic oxygen from the photodissociation of molecular oxygen and the higher atmospheric density needed to produce the 3-body collisions (O2 + O + M) to conserve momentum and kinetic energy.”

    You also left out that she was only discussing photodissociation, when I re framed the question to include NOx she agrees that EUV and FUV ARE responsible to a large extent for the ozone modulation and production in the 50-70km region. End of story.

    Joanna when stating there was “little evidence that EUV and FUV had any influence on the climate” she is talking about actual EUV and FUV absorption rates at lower levels. She agrees there are upper stratosphere and mesosphere influences from EUV and FUV. Those influences are linked (by others) to the break down of the polar vortex which in turn influence the jet stream, we are witnessing this phenomenon right now throughout Europe (real world observation). Have you not been watching the AO/QBO and jet stream patterns along with the sudden weakening of the upper stratosphere zonal winds and ozone changes in this area?

    If you want more I suggest you read Baldwin and Hood and the plethora of scientists behind them. I suspect it wouldn’t matter what science is presented, you have fixed views or agenda.

  239. Geoff Sharp says:
    February 9, 2012 at 3:11 pm
    Joanna when stating there was “little evidence that EUV and FUV had any influence on the climate”
    She was clearly and simply stating the generally accepted fact that there is little evidence that EUV or FUV have any influence on climate. It being understood that climate is what we experience on the ground. That EUV and FUV control the thermosphere, ionosphere [my specialty], and upper mesosphere is well known and not something you need to ask around for, but it is also well-known that the ozone produced in the upper mesosphere is less than a 1/10,000 of that produced in the stratosphere by the dominant radiation above 200 nm, and so it is no surprise that EUV/FUV is not a key player in climate. You may specifically have asked about the mesosphere. I specifically asked about the climate and the answer was clear.

  240. Leif Svalgaard says:
    February 9, 2012 at 9:36 pm

    You are floundering, there is no doubt ozone is controlled at different levels by UV that fluctuates greatly over the cycle.Whether it be 6% or 100% depending on the wave length they each play their part. The obvious elephant in the room is that TSI cannot compare with its smaller variation. But of course TSI variance is still not yet empirically known over the longer term. Many scientists are aware of the top down chemical processes that affect climate, your insistence to ignore this science says a lot.

    Like I said there is real world observations of this process in action. I have prepared a table of these real world metrics that document the process that causes the “Great Winter Freeze of 2012″. It can be found at the end of the following article.

    http://tinyurl.com/2dg9u22/?q=node/236

  241. Geoff Sharp says:
    February 9, 2012 at 10:15 pm
    Many scientists are aware of the top down chemical processes that affect climate, your insistence to ignore this science says a lot.
    I’ll go with Haigh and Lockwood that EUV/FUV are not significant drivers of climate. That EUV/FUV are controlling conditions in the thermosphere/ionosphere/upper mesosphere is equally not in dispute [I use that in my own research], but, again, there is no evidence that that has anything influence on the climate, no matter how badly you want it to have.

  242. Leif Svalgaard says:
    February 9, 2012 at 10:23 pm

    I’ll go with Haigh and Lockwood

    Sounds like cherry picking to me.

    I will go with Haigh, Solomon, Hood, Baldwin, Salmi, Gray, Dunkerton, Hamilton, Haynes, Randel, Holton, Alexander, Hirota, Horinouchi, Jones, Kinnersley, Marquardt, Sato, and Takahashi. This is a small sample of published atmospheric scientists that clearly associate solar UV changes with downstream climate forcing.

  243. Geoff Sharp says:
    February 9, 2012 at 11:29 pm
    scientists that clearly associate solar UV changes with downstream climate forcing.
    But not EUV/FUV as Haigh so clearly states. The dominant contribution to ozone in the stratosphere is from UV above 200 nm.

  244. Geoff Sharp says:
    February 9, 2012 at 11:29 pm
    scientists that clearly associate solar UV changes with downstream climate forcing.
    You may want to ponder that there has been no trend in EUV since the 1720s.

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