1815, 1816 and 1817; A POLAR PUZZLE

An attempt to stimulate discussion about the causes of an unexpected event which occurred after the huge eruption of Tambora Volcano in 1815

Guest Essay by Caleb Shaw

Volcanoes cause cooling, right?  No.

Having got your attention, I would like to bring up three historical incidents, hoping I may generate some interesting explanations for something I myself have no definite answer to.
On April 10, 1815 the Tambora Volcano exploded.  It is estimated it blew 39 cubic miles of ash skywards. (A three-mile by three-mile by three-mile cube is only 27 cubic miles.) (I have no idea how many Manhattans that is.)

The noise was so loud it was heard 1200 miles away. Ships over the horizon assumed it was the cannon of a ship in distress and sailed around looking for another ship, and on one island troops were marched off to reinforce other troops because it was assumed an outpost was under attack.  Then the great cloud of ash began to spread across the sky.
It is estimated 10,000 people were killed immediately by the blast, as many as 70,000 more by starvation or diarrhea brought on by the heavy ash fall, and another 4600 by tsunamis ranging from six to thirteen feet. The blast, as large as four Krakataus, penetrated the tropopause, roughly 11 miles up near the equator,  and reached 16 miles further into the Stratosphere, to a total height of 27 miles.  There, high above the circulations of Haley and Ferrel Cells, it began to spread out around the Globe.

By June 28, 1815 the inhabitants of London were noting amazing, brilliant and long-lasting sunsets.

The following summer, 1816, was remarkably cold over many northern lands, marked by frosts and ruined crops.  It is remembered as “The Year Without A Summer” and, in my neck of the woods, as, “The Year Of Eighteen Hundred And Froze To Death.”  Here in New Hampshire, where hay was an export that fueled the horse-drawn transport big cities, not even enough grass could be grown to feel local livestock. While the wealthy could import hay from Pennsylvania, the poor knew hunger, and many simply had to slaughter their livestock.  In the following years populations of many towns in New England shrank, as people never wanted to see such a summer again, and the rock-free lands of Ohio sounded warmer, and actually were further south.

The link between Tambora and that cold summer seems plain, but here comes the third and, to me, intreauging item from 1817.  It involves a quote from John Daly’s site which many know well, that begins,

“It will without doubt have come to your Lordship’s knowledge that a considerable change of climate, inexplicable at present to us, must have taken place in the Circumpolar Regions, by which the severity of the cold that has for centuries past enclosed the seas in the high northern latitudes in an impenetrable barrier of ice has been during the last two years, greatly abated….”

This statement by the President of the Royal Society in London is dated November 20, 1817, and is not what I would have expected.  I would have expected Tambora to increase the ice at the pole by making the entire earth colder.  The fact the ice apparently decreased is a polar puzzle.

The question then becomes, “Do volcanoes reduce the amount of ice at the poles?”
In the comments at WUWT the commenter Philip Bradley suggested that Tambora’s ash may have fallen on the polar ice, reducing the albedo and increasing the melting.  I’m not sure enough ash would fall, that far north, and remain uncovered by snow long enough, to have such a dramatic effect.

I’d be interested to hear the ideas of others.  My personal guess is that, even though the climate was colder back then, the AMO still went through warm and cold phases, and just happened to be moving into a warm phase, involving a slosh of warmth moving north, and Tambora accentuated this slosh.

As I have explained elsewhere, “I call this my Slosh Theory, and it is based upon a highly scientific experiment I did at age three in the bath tub. Timing was everything. If you got the timing down, you could generate such a tremendous wave that half the water left the bathtub and wound up on the floor.

My mother did not appreciate my research and stunted my scientific growth, which explains why I became a writer.”

About these ads

158 thoughts on “1815, 1816 and 1817; A POLAR PUZZLE

  1. Does it follow then that perhaps the Arctic Ocean was ice-free during the ice-ages?? That would certainly help providing all the precipitation needed for the ice-sheets.

  2. I think the most likely explanation is that the President of the Royal Society was talking codswollop. It’s happened since. Probably overheard someone in a bar complaining about lack of ice in the drinks, or that some whaling ship actually got back to port when it was supposed to.

    One point, the ash apparently went towards the N/NW, which winds occur in the dry season from ~April to ~October. Sicne Tambora is just south of the equator (and not far from where I work in East Nusa Tengarra), that’s a long way to the north pole.

  3. The question of the full response to volcanoes is interesting.

    http://climategrog.wordpress.com/?attachment_id=318

    There is a clear rebound reaction from climate system. This far too quick to be a general drifting back due to AGW.

    That rebound would seem to come from tropical oceans. Once this warming pulse hits the upper troposphere , so will go polewards.

    In an extreme event this may explain what you ask about .

  4. Here is the cumulative integral of the same thing:

    http://climategrog.wordpress.com/?attachment_id=310

    Here flat means same mean temp as before the events. Up slope is warmer (rather than warming) ; down slope is cooler than before.

    clearly tropics auto regulate and maintain there average _accumation_ of degree.days. (Growth days to farmers)

    This means that they must have a period that is _warmer_ than average to match any days that were cooler.

    There are two possible sources for this heat energy.
    1. reduced cloud cover (less tropical storms) catches a higher percentage of the reduces solar available
    2. Heat from subsurface layers of the ocean warms surface. This may account fo some studies showing “El Nino like” conditions a few years after major eruptions.

  5. corr.
    1. reduced cloud cover (less tropical storms) enables ocean surface to catche a higher percentage of the reduced solar available

  6. When paleo-climatologists take ice cores in Greenland, do they by any chance record the amount of ash/dirt/soot found in each “ring” while they are looking for the CO2 in the air bubbles?

  7. Albedo only comes into play while the sun is up in the northern polar regions and imho is the least of four factors affecting the melt of sea ice. Most of the thaw is due to wind blowing the ice out into the atlantic (during winter), wave motion breaking up the ice into smaller, less insulated bits and the interactions between freezing air temperatures and close to freezing sea water against the ice layer.

    My money would be on changes in the northern polar air circulation induced by the high altitude ash that increased wind flow to drive out polar ice to melt in the Atlantic and away from the shores.

    It would thus be interesting to look at reports from ships regarding icebergs between late 1815 and mid-1817 to see if there’s an increase in ice flow to the northern atlantic. Considering the event of global impact may also leave residue in ice cores, although timing them precisely enough to be of use seems rather impossible (hard enough to distinguish 5 year periods, much less whether it deposited in summer or winter).

  8. For those pushing the carbon or anything-but-solar-driven climate, volcanoes provide a handy fudge factor. Simply plug in the missing energy from the climate system and say it was from volcanoes, and voila. Pretty good system, really.

  9. While researching the early New England settlers from Kent it was interesting to read that in the mid 1600s the winter Polar Ice extended down to modern day Rhode Island .
    I think the President of the Royal Society was quite right in 1817 and without the ‘benefit ‘ of post normal science which characterizes too many of today’s climate pronouncements.

  10. Shortly after I submitted this article the blogger “Tonyb” pointed out there was a “mystery eruption” roughly as big as Tambora only seven or so years earlier, as shown sulfates in by ice cores.

    Tonyb wrote a wonderful history and posted it on WUWT four years ago. It is a treasure trove of information about arctic sea ice:

    http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/

    After further thought, I should have included the “mystery eruption” in my brief history. The arctic was likely feeling the after effects of the “mystery eruption” when the effects of Tambora hit.

    Just imagine if two such eruptions occurred in only seven years, these days!

  11. I doubt the President of the Royal Society was talking codswallop at all. Back then they tended to be far more serious & professional. The fashion for putting ice into drinks was a rare one indeed back then. Sir Joseph Banks was a Naturalist & patron of the sciences. They were God fearing back then too. As a nation building an empire Britain needed a mighty navy to protect & service that empire. Banks’ letter also noted that the area could be opened up for exploration & trade as a result of this “new source of warmth”. They had to be good setting themselves above the rest. Admittedly Lord Kelvin is reputed to have said in1895 that “heavier than air flying machines are impossible!” I suspect that the distance was not as great as one might think for dust & ash to travel, I seem to recall the Mount St Helens eruption sent ash & dust circulating the globe over 2-3 years!!!!! It may be linked may be not, although we do know (sort of) that the Arctic has been ice-free in the past, & probably will be again, through perfectly natural processes! Me? I take a leaf out of Doug L. Hoffman’s book, “enjoy the interglacial, stay sceptical!” ;-)

  12. I’ll try again. Please remove this if it is a duplicate.

    Shortly after I submitted this article the blogger “Tonyb” pointed out there was a “mystery eruption” roughly as big as Tambora only seven or so years earlier, as shown sulfates in by ice cores.

    Tonyb wrote a wonderful history and posted it on WUWT four years ago. It is a treasure trove of information about arctic sea ice:

    http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/

    After further thought, I should have included the “mystery eruption” in my brief history. The arctic was likely feeling the after effects of the “mystery eruption” when the effects of Tambora hit.

    Just imagine if two such eruptions occurred in only seven years, these days!

  13. Greg Goodman says:
    July 8, 2013 at 3:49 am

    Interesting. There was a “rebound” after Pinatubo in the form of the super-el-nino of 1998. Coincidence?

    If there was a big ENSO event after the “mystery eruption,” it might have been occurring right when the effects of Tambora began.

  14. How about the following armchair idea, absolutely unsupported by any scientific analysis (I know I know): Perhaps all that material blasted up did not in fact have any effect on the total energy balance of the globe but merely changed the way the energy was distributed around? It had to go somewhere! That would perhaps imply a far more robust stability in the entire system than seems to be commonly acknowledged. Almost an immunity to minor ‘forcings’. (I hate that word!) May apply to other factors also…

  15. To Alan the Brit:

    As much as I admire most of the individuals and scientific traditions of the Royal Society in the 1800s, they still got it badly wrong from time to time.

    Lord Kelvin also got it hopelessly wrong with regards to the age of the earth, stating that the earth couldn’t be more than ~100 million years old (from memory) due to calculations he made based on measured heat flows and an assumed uniform rate of cooling of a sphere over time from the heat within the earth generated from the early solar system formation. The stratigraphers were adamant that the rocks were much older. Lord Kelvin, in the usual tradition of eminent physicists ignoring those who study rocks in the field, decided to totally ignore them. The stratigraphers turned out to be right, when radioactivity was discovered just a few years later, which produces a constant amount of heat, enabling the earth to be much much older than Lord Kelvins calculations (The story is described well in one of SJ Gould’s books) (Incidentally, this scientific feud and general arrogance of physicists towards geologists has a long history, Einstein rejected plate tectonics, Alvarez rejected any notion that volcanos had anything to do with the K-T extinction, and even John Cook of ‘sceptical science’ (who is a solar physicist, although I don’t wish to use his name in the same breath as the other two)- rejects the greater portion of economic geologists who claim that warming in the 20th century is mostly natural. (In a study on his website, it found that >50% of practising exploration geologists do not think 20th century warming was mostly from human activities.)

    To qualify what I suspect, I suspect that the President of the Royal Society might have indeed have been reporting a vague story that the ice had declined in recent years, but that this had also been going on for some time, since the middle of the Little Ice Age, around ~1700. It was perhaps only once it made it to the ears of those important that is began to be more widely reported. In other words, bureaucratic exaggeration at a time when perhaps the passage was beginning to become more passable. But that is just my gut feeling, I could of course be completely wrong, but I’d like more evidence.

    Also, in April, the winds around Sumbawa and Tambora are light, no more than about 5-10mph from the SE, as the trades are just starting at that time of year. They are so light in April that they sometimes blow the other way. So the ash wouldn’t have gone very far, August-September would have been better, the trade then blow around 20-30mph almost every day towards the northwest.

  16. I am strangely drawn to the codswallop explanation (although I would call it the more genteel “anecdotal evidence” lacking any sort of systematic measurements or assessment beyond this anecdote). If we accept this folderol — however anecdotal — as true, note that:

    a) Volcanoes output a rather large amount of aerosols. Tambora in particular blew 38 cubic miles of earth into the air, and was estimated at 800 megatons of TNT — the equivalent of a full-scale nuclear exchange with hundreds of 1 to 5 megaton warheads being used. The dust and ash and aerosols would have had a mixed effect (as such things often do). Aerosols nucleate cloud formation. Clouds have a much higher albedo than land or ocean. In the tropics, they tend to be net cooling (by reflecting away much of the incoming sunlight during the day). At the poles, however, they can easily be net warming, as they are a “greenhouse” cover that reflects heat back towards the earth. The ash and particulates themselves also very likely had a mixed effect, but one that is net cooling in the low latitudes and net warming in the upper latitudes.

    This simple heuristic explanation is, of course, probably wrong. That’s the trouble with climate science — too many simple, linear, heuristic explanations (often “explaining” evidence so thin and from such a short baseline it might as well be anecdotal) turned into components in a nonlinear chaotic model. The problem with events like this one is that we have damn-all data on what they might do to the Earth’s ecosystem or climate. They simply don’t happen all that often, and they are so much beyond the more modest Pinatubos of our day that they very likely trigger nonlinear responses one cannot imagine from linear extrapolation of smaller volcanic eruptions, or eruptions at different latitudes (as where the explosion happens in the jet stream probably does, as previously noted, matter). This is doubly true when it is noted that a substantial amount of material went into the stratosphere, where it might have altered stratospheric chemistry altogether for a decade or more. The stratosphere is changing right now (its moisture content is decreasing substantially) and we don’t really understand why. Nor do we understand why there is less anecdotal (more substantiated) evidence that the Arctic warmed and a lot of the polar ice melted back in the 1930’s, without any help from human-generated CO_2 or a volcano. We have little to no idea what Antarctica was doing at that time as well, as it was still almost completely terra incognita then (and still is, to be honest, now, except for satellites).

    rgb

  17. There isn’t actually that much precipitation (as snow or anything else) at the poles – that is why they are often called polar deserts. So it is possible that the ash affected the albedo of the ice for a significant time.

    In addition, cloud cover at the poles actually has a warming effect. My understanding is clouds are high albedo, but naked ice is higher. So if the ash from the eruption caused a global increase in cloud cover, this might have actually resulted in greater insolation heating in polar regions.

  18. In my neck of the woods, overcast winter days are always warmer. A cloud cover seems to suppress the radiative cooling. A crystal-clear, low-humidity day will usually be quite cold. It is not unreasonable to think that, depending on the aerosol mix that made it around the globe some of the radiative cooling of the arctic regions could have been suppressed.

    However, this is the problem with one-off historical events. With very few exceptions, in the absence of reliable forensic analysis, there simply are not enough carefully recorded observations to draw many scientific conclusions. An exception to this was a celestial phenomenon over the skies of St. Petersburg in 1790 (see http://spie.org/etop/1991/378_1.pdf for Robert Greenler’s excellent analysis). That was a case in which a particular atmospheric scattering event was so carefully documented that 200 years later, Greenler was able to take the recording and deduce exactly what was being observed. Now that’s science.

  19. Correction: It should have read ‘atmospheric’, not ‘celestial’, even though the observer at the time couldn’t necessarily distinguish the two.

  20. Here’s another armchair idea — the decrease in ice referred to in the quote was a decrease in the number of icebergs, since back then polar explorers did most of their exploration by ship. Icebergs are driven by melting at the fringes of the ice sheet. Hence a brief, volcano-related cold snap would reduce the polar melting and decrease the number of icebergs at the same time that the land-based ice-sheets were expanding. Thus sea captains correctly saw that sailing north had gotten easier.

  21. As I have explained elsewhere, “I call this my Slosh Theory, and it is based upon a highly scientific experiment I did at age three in the bath tub. Timing was everything. If you got the timing down, you could generate such a tremendous wave that half the water left the bathtub and wound up on the floor.

    The phenomenon exists in lakes and other basins and is called a seiche. The wind piles the water up on one side of the basin and, when the wind quits, the other side of the basin gets flooded.

    The basin acts like (or actually is) an underdamped second order system. Such systems oscillate (ring) if they are stimulated. They will overshoot, undershoot and eventually settle back to their steady state value. To my eye, the heating in 1998 looks like a response to the eruption of Mount Pinatubo.

  22. “Interesting. There was a “rebound” after Pinatubo in the form of the super-el-nino of 1998. Coincidence?”

    Mt P. is one element in my volcano stack (six largest in thermometer period). The other relevant factor is that the “dip” was not all volcanic. My first link shows a down turn underway before the “average” eruption.

    This was the case for the last two. There is a lot of false attribution going on here.

    I discussed this on SteveL recent regression article @ lucia’s blackboard. He was not at all receptive to any “nonsense” about possible cycles (even 60y) in climate so generally ignored my comments and point blank refused to post the residuals from his regression attempt.

    Something akin to the Phil Jones ” why should I give you my data , you only want to find something wrong with it”. philosophy.

    One interesting thing his fairly broad range of regressions showed , was that if you include data back to 1950 (rather than just >1979 warming period) and AIC test shows a polynomial fits the data better than any combination of the solar+volcano “forcing” inputs.

    I pointed out that this meant his set of input variable was insufficient . He ignored that totally.
    I suggested there is likely a 9y component (which Curry/BEST just published on) and that this roughly coincides with the last two eruptions.

    This was why I wanted to examine his residuals, for evidence of this.

    That request got a blunt refusal and insult about my mental health. LOL

    Long live objective scientific investigation.

    The upshot is volcanic signal does not fit well unless you blinker the data down to just around those two events, at which point it can be regressed against both the volcanic signal and the concurrent 9y cycle.

    Similarly Nick Stokes did a similar regression attempt which showed ENSO tending to correlate opposite to volcanism. This is further evidence of a compensatory tropical climate reaction.

    Since ENSO is not really “exogenic” forcing anyway, I read that as being a linear “correction” (fiddle factor) for a non-linear climate response that is being modelled as linear.

  23. Globally increased clouds through volcanic ash cloud?

    Will cool tropical regions, but provide more insulation at the poles. As the gulfstream will have trundled on as before, given the momentum of the many cubic kilometers of water involved, the heat flow from the equator to the north is more or less the same, but losses through cloud cover are reduced. Hence more melting sea ice.

  24. I am no scientist or historian. The idea I have is very simple. It is possible that the volcanic ash acts like road salt. Road salt does lower the melting point of the snow to help keep the snow and ice from refreezing near the original freezing point. Pumice is one of those that we use on some city streets either with or substituting road salt. My question is is volcanic ash a form of pumice? Because if volcanic ash is actually a form of pumice, its characteristics with lowering the melting point of snow and ice could have something to do with the decrease in the sea ice in 1817.

  25. Kaboom says: Albedo only comes into play while the sun is up in the northern polar regions

    This is the alarmists myopic view of what albedo means. Albedo is reflectivity and is spectrally dependant. It applies at all times of the year and affects emission as well as absorption.

    Open water is nearly “black” in the IR spectrum. Far from producing the “tipping point” positive feedback that many predicted by only considering the reflection of incoming solar, there is also a negative feedback through more IR emission and this works 12 months of the year.

    An increase of ice after such a major eruption would just be a manifestation of this same negative feedback working in the other sense.

  26. @rgbatduke >> At the poles, however, they can easily be net warming, as they are a “greenhouse” cover that reflects heat back towards the earth. <<

    And during the polar winter, the same high-altitude reflective effects that make for spectacular sunsets could reflect more sunlight towards the poles, providing additional warming energy.

  27. Sorry I can’t provide a link, but I remember reading that after the end of the Napoleonic wars the Portuguese cod fishermen, and European whalers, found that there was much less ice in the north than there had been when they were there regularly before the N wars started some 20 years earlier. I think the article I remember was a British Admiralty collection of reports from various shipmasters.

  28. Another example of the Royal Society’s getting it badly wrong is described by Bill Bryson in his book ‘A short history of nearly everything’. In the mid-19th the Society awarded its highest honour, the Royal Medal, to palaeontologist Richard Owen, who had falsely claimed to be the discoverer of fossil organisms which had in fact been discovered and reported by other, less influential, scientists.

  29. I says: “An increase of ice after such a major eruption would just be a manifestation of this same negative feedback working in the other sense.”

    oops, meant decrease. This neg. f/b would oppose the presumed reaction tending to produce more ice (that is the sense of a negative feedback). Whether there is a net increase or decrease will depend upon many other factors, But this will tend to limit extreme excursions and avoid “tipping points”.

  30. The ash cooled the planet just as clouds block incoming solar radiation. But, do not forget that clouds act as a blanket to slow down atmospheric and surface cooling, just like a blanket on a person’s body. Clouds DO NOT warm the surface or atmosphere, they just slow down its radiative cooling. Think about how rapidly air cools on a hot, partly cloudy summer day, quickly forming surface breezes as the air under a moving cloud rapidly, in seconds, radiates away its energy.

    Particularly during the long night and extended twilight, there would not be many clouds in the Arctic, but the ash would have acted as clouds and prevented the Arctic from the radiative cooling that it would have done unopposed during the long Arctic night. That means the Arctic night would be warmer than normal.

  31. Large stratospheric eruptions leave a thinner Ozone layer in their wake. Going by the last 3 large eruptions, it can take more than 25 years for the Ozone to rebuild and there can be a cumulative impact from successive events.

    While the thinner Ozone is in place (and after the ash/sulfate cloud dissapates over the following 3 years), more ultraviolet solar radiation is getting through the atmosphere and reaching the surface.

    Climate science seems to be unwilling to address this issue. Ozone has both a shortwave (solar interception) component and a longwave (greehouse gas) component and they haven’t really crunched the numbers on the net impact. But going by the temperatures in the stratospheric Ozone layer which are reduced by -0.5C to -1.0C in the long-run after an eruption, it appears that volcanoes could have a long-term warming impact until the Ozone rebuilds over several decades.

  32. RE: lsvalgaard says:
    July 8, 2013 at 5:03 am

    Thanks for pointing that out, Leif. I’d forgotten the Mayan Volcano in 1814.

    So now we have the “mystery volcano,” Mayan Volcano, and Tambora, all messing up the tidy calculations of regular cycles, all within ten years.

    Is it any wonder weather is such a challenge to forecast? You go through all the work of carefully plotting the weather for the next year, and then some dumb volcano pops, and you might as well throw your forecast into the trash. I can just imagine a meteorologist throwing a pile of papers, read-outs and maps into the air in disgust, and scrabbling his hair with a deranged look.

    Of course, if we could forecast volcanoes…..

  33. The super-volcano Krakatoa eruption of 1883 occurred in Sunda Strait, geophysically adjacent to Tambora in the Lesser Sunda Islands. So the comparative question is, what influence (if any) did Krakatoa have on far-removed North Polar regions? Though any Arctic icecap thinning would be noticeable only on a major scale, we wonder if records exist to corroborate Tambora’s apparent warming-pulse some 67 years before.

  34. When a volcano punctures the atmosphere to 27 miles, it provides a strong conductive path from the lower regions of the ionosphere to the Earth. There must have been a huge electrical surge at the location of the volcano that drained a significant portion of the Earth’s outer (ionospheric) electrical charge. This change in charge would alter the polar electric atmospheric boundaries, particularly over Greenland and Northern Europe, thus allowing the cold air of the Arctic to flow south. The warmer air from the Eastern Pacific and Asia would migrate north to replace the Arctic air and thaw the polar ice.

    I think this is what we are seeing on a smaller scale even now as the Eastern portion of the US experiences cooler weather and the Western portion bakes in a stalled high pressure system. What we are seeing right now is the beginning of a long term Maunder minimum type event that will cool the Eastern US and Europe while warming the Arctic. The cause of the present electrical breakdown of our atmospheric systems is the weak electrical output of the Sun.

    Incidentally, it also appears that the Earth is going through a separate long term cycle of internal heating on a scale of ten to twelve thousand years. We appear to be experiencing an increase in volcanic and background seismic activity. This will inevitably lead to large volcanic explosions, which could potentially puncture the atmosphere and further degrade the Earth’s electric charge. We could be heading for a catastrophe of biblical proportion.

  35. steveta_uk says:
    July 8, 2013 at 3:59 am

    When paleo-climatologists take ice cores in Greenland, do they by any chance record the amount of ash/dirt/soot found in each “ring” while they are looking for the CO2 in the air bubbles?
    >>>>>>>>>>>>>>>>>>>>
    Some do.

    NY state Univ @ Buffalo Study of Dust in Ice Cores Shows Volcanic Eruptions Interfere with the Effect of Sunspots on Global Climate

    Sun/dust correlations and volcanic interference
    We examine the relationship between the GISP2 dust profile, a proxy for the Northern Hemisphere atmospheric dust load, and the Wolf sunspot number, a proxy for solar activity. The two records are positively correlated, but the phase of the relationship is disturbed by the effects of explosive volcanism. Similar correlation failures have already been noted for many other climatic indicators. Our work suggests that a large fraction of the correlation failures may be attributed to explosive volcanic activity.

  36. From space we see that the ups and downs of sea ice numbers is all about the wind. Kaboom got it right about the wind blowing sea ice into the north Atlantic, it also blows it here and there. Pileing it up to 5 meters thick or thinning it down to less than 0.5 meters thick. Sea ice area, extent,or volume are not a proxy for global warming, they are however a proxy for the wind.
    Icebergs are generaly made from glaciers not piled up sea ice.

  37. “My mother did not appreciate my research and stunted my scientific growth, which explains why I became a writer.”

    A Youshrieker moment.

  38. Kaboom
    July 8, 2013 at 4:03 am

    Indeed the winds did blow the ice out of the Arctic in 1816 as illustrated from Hudson Bay Company log books. Go to:

    arctic.synergiesprairies.ca/arctic/index.php/arctic/article/download/…/209…‎

  39. Maybe a persistent pattern of southerly wind pushed ice north of the routes normally traveled, thus giving a false appearance of being warmer even though global temperatures dropped as a result of volcanic ash.

  40. The Greenland oxygen isotope record shows that there was a warming period taking place between 1810 and 1820, peaking in 1820. AMO was negative and PDO was positive during this period. The last El Nino was about 1814. I think a change in Arctic wind pattern and direction can cause a major change in ice conditions. I tend to lean on the wind factor as the possible cause.

  41. RE: David Thomson says:
    July 8, 2013 at 6:48 am

    That’s an interesting idea about the tower of ash acting as a channel for electric currents. Of course, I have no clue how scientific the idea is, but I like it just the same.

    I am always reading ideas about the electric and magnetic and gravitational and chemical actions and reactions that go on around us, every day, well aware some of theories are dubious, to say the least, but glad because through such theories I become aware of how fabulously intricate and complex our World is.

    One time I was reading about various chemicals ending in “i-n-e” reacting with Ozone in the upper atmosphere. After reading about Chlorine, Bromine, and Florine, I chanced upon an off-hand comment about Iodine, stating it was from plankton in sea spray. My eyes sort of crossed in wonder, as I thought about this little bit of plankton cruising about the stratosphere, likely muttering to himself, “Mamma told me not to go out to that party, but did I listen?”

    Its good we have sensible thinkers to bring us back down to earth with a thump. Not that I always enjoy the experience, but it pays to be well grounded.

  42. Try out this idea. Most of the year, The air above the poles is warmer than the surface (inversion). Ash not only reflects energy from the sun, it absorbs it. That ash that is transported from the equator to the poles in the upper atmosphere gains energy on the way. Half of that energy is radiated downward, so at the poles, the surface can be warmed by the ash in the upper atmosphere.

  43. the severity of the cold … has been during the last two years, greatly abated
    ==========
    What the President of the Royal Society is talking about is the cold, not the ice. This is consistent with the cold polar air breaking out of the Arctic and resulting in cold weather in more southerly areas.

    The earth generally has 3 bands of circulation between the equator and poles. The westerlies insulate the temperate zones from the polar air to the north. However, if there is a breakdown in the westerlies such that there is only 2 bands of circulation, or more likely only 1 band of circulation, then there is nothing to contain the polar air and it is likely we will enter ice age conditions.

  44. My thinking as to what was going on is along similar lines as to what David Thomson is saying.
    lt looks to me that the Polar jet pushed deep to the south over large area’s of the NH, but then would at times swing northwards to push up into the Arctic and then would come back down south again. lt was these large swings in the Polar jet l think that caused the cooling futher to the south but warming in the Arctic. l think the closest match we have in recent years to what was going during the summer of 1816 in europe at least. Was the summer of 2012.
    Because it seems that in the summer of 1816 the cold wet weather was mostly in the western half of europe with warmer weather over on the eastern side of europe. This is similar to what happen during the summer of 2012.

  45. To make things even more interesting, the cold period associated with the Dalton Solar Minimum occurred from about 1790 to 1820 so 1814 would be well within it and the polar area should have been colder. The problem is, we really don’t know from the brief description whether or not it was typical of the whole Arctic.

  46. No one ever wants to look at submarine sources of heat. At least 75 percent of the Earth’s volcanoes lie beneath the surface of the ocean. Did the eruption of Tambora signal a general increase in vulcanism on the Earth? If so, how much heating would sub-surface ocean vulcanism impart to ocean water, and hence to the ice pack? Quite a bit of heating I suspect. You can find any number of videos on Youtube of submarine volcano eruptions which help to illustrate: http://www.youtube.com/watch?v=91IMATayaFo

    There are many ancestral legends from people all over the world about “boiling oceans,” as well as modern day examples of apparent undersea heating activity correlated with tectonic activity. Here is an example from the Phillippines: http://www.globalpost.com/globalpost-blogs/southeast-asia/philippines-boiling-sea

  47. If the westerlies weaken to the point that they no longer contain the polar air, then the polar air will flow to the equator along the surface, be heated at the equator and rise, and flow to the poles at altitude. This will make the poles warmer and wetter, and the temperate regions cooler and drier. Duplicating ice age conditions.

    Perhaps a reduction in solar energy reaching the surface is all that is required to reduce the strength of the westerlies, allowing us to slip into the next ice age.

  48. RE: JFD says:
    July 8, 2013 at 7:24 am

    Something was really moving the ice about back then. I got the following quote from that treasure trove of old records Tonyb put together, that I mentioned and linked to back at 4:12 AM. The quote is from 1817.

    “We learn that a vessel is to be fitted out by Government for the purpose of attempting again the north-west passage, the season being considered as peculiarly favourable to such an expedition. Our readers need not be informed that larger masses of ice than ever were before known have this year been seen floating in the Atlantic, and that from their magnitude and solidity, they reached even the fortieth latitude before they were melted into a fluid state. From an examination of the Greenland captains, it has been found that owing to some convulsions of nature , the sea was more open and moiré free from compact ice than in any former voyage they ever made: that several ships actually reached the eighty-fourth degree of latitude, in which no ice whatever was found; that for the first time for 400 years, vessels penetrated to the west coast of Greenland, and that they apprehended no obstacle to their even reaching the pole, if it had consisted with their duty to their employers to make the attempt…”

  49. thingodonta says: (July 8, 2013 at 4:42 aM)

    Also, in April, the winds around Sumbawa and Tambora are light, no more than about 5-10mph from the SE, as the trades are just starting at that time of year. They are so light in April that they sometimes blow the other way. So the ash wouldn’t have gone very far, August-September would have been better, the trade then blow around 20-30mph almost every day towards the northwest.

    I suspect that an event of the magnitude of Tambora way well have made any conventional wisdom about the local weather and winds patterns completely irrelevant for some months if not years.

  50. henry@caleb
    Before they started with the carbon dioxide nonsense, people looked at the planets to explain weather cycles, rightly or wrongly.
    see here

    http://www.cyclesresearchinstitute.org/cycles-astronomy/arnold_theory_order.pdf

    to quote from the above paper:
    “A Weather Cycle as observed in the Nile Flood cycle, Max rain followed by Min rain, appears discernible with
    maximums at 1750, 1860, 1950 and minimums at 1670, 1800, 1900 and a minimum at 1990 predicted.
    The range in meters between a plentiful flood and a drought flood seems minor in the numbers but real in consequence….

    end quote

    Acording to my table for maxima,

    http://blogs.24.com/henryp/2013/02/21/henrys-pool-tables-on-global-warmingcooling/

    I calculate the date where the sun decided to take a nap (this is just a figure of speech) , as being around 1995.
    and not 1990 as William Arnold predicted.
    This is looking at energy-in. I think earth reached its maximum output (means) a few years later, around 1998 or 1999

    Anyway, look again at my best sine wave plot for my data

    http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/

    now see:

    1900 minimum flooding – end of the warming
    1950 maximum flooding – end of cooling
    1995 minimum flooding – end of warming.
    predicted 2035-2040 – maximum flooding – end of cooling.

    Do you see the pertinent correlation with my sine wave?

    Now from the report here:

    http://wattsupwiththat.com/2008/03/16/you-ask-i-provide-november-2nd-1922-arctic-ocean-getting-warm-seals-vanish-and-icebergs-melt/

    the relevant newspaper reports severe melting of arctic ice more than two decades AFTER the end of warming 1900.

    This is how long earth stores its energy in the oceans,
    So the report of severe melting of the arctic ice in 1817, nearly two decades after the end of warming 1800 as noted from the flooding of the nile, CAN BE EXPECTED, if you allow for a general 5 year error either way, on my sinewave. It is natural, and it had nothing to do with the volcanoes..

    By 2040 everything will freeze up there again in the arctic and we will be back to where we were in 1950!

  51. “thingodonta says:
    July 8, 2013 at 3:46 am
    I think the most likely explanation is that the President of the Royal Society was talking codswollop. It’s happened since.”

    ########################

    this is a funny post and I’d like to highlight several things.

    There is a constant refrain about climate science being “all models” and a constant demand for “data”. I should like to remind people that a historical report is not data.

    There is also a constant refrain about appeals to experts. Please note it matters little whether this guy was the janitor or the president of the royal society.

    Occams razor is also raised many times here. So we have a “mystery”. That mystery vanishes if we adopt the “codswollop” interpretation. Please note all the byzantine explanations that pop up if you reject the “codswollop” interpretation.

    And finally note how easily most people accepted the “mysterious” data without question. Without questioning the source, without checking its reliability, without noting that there is virtually no way of calibrating the statement. What exactly was he talking about? what was measured? by whom? This is not to say that we should discount all historical accounts. historical accounts are words on a page. they are not data. you can’t take the standard deviation of words on a page. you cant go back and repeat the experiment. By epistemic standards historical accounts are worse than models. But despite these difficulties there is some value in historical accounts. That value is merely this: A historical account can give you an interesting question to ask.

  52. RE: Bob Tisdale says:
    July 8, 2013 at 8:08 am

    Thanks, Bob. I could only glance at the paper, as I’m already in trouble for skipping work to read all the neat comments. Is this research about the winter immediately after an eruption?

    As I recall, the winter right after Pinatubo surprised me by being mild, but the next summer my tomatoes refused to ripen. I think I only got eight by the first frost, which was early. Every window sill in the house had green tomatoes sitting on it. Then the second winter was very cold.

    I wonder if the reaction to volcanoes is a two step process. First the flow gets very zonal, and second goes all loopy with blocks?

    No I must sadly bid adieu for a bit. There are those in this world who think a broken belt on a mower is more important than WUWT.

  53. “I should like to remind people that a historical report is not data.”

    Really? What exactly do you think data is?

  54. I wonder what hqappened to my post?
    henry@caleb
    Before they started with the carbon dioxide nonsense, people looked at the planets to explain weather cycles, rightly or wrongly.
    see here

    http://www.cyclesresearchinstitute.org/cycles-astronomy/arnold_theory_order.pdf

    to quote from the above paper:
    “A Weather Cycle as observed in the Nile Flood cycle, Max rain followed by Min rain, appears discernible with
    maximums at 1750, 1860, 1950 and minimums at 1670, 1800, 1900 and a minimum at 1990 predicted.
    The range in meters between a plentiful flood and a drought flood seems minor in the numbers but real in consequence….

    end quote

    Acording to my table for maxima,

    http://blogs.24.com/henryp/2013/02/21/henrys-pool-tables-on-global-warmingcooling/

    I calculate the date where the sun decided to take a nap (this is just a figure of speech) , as being around 1995.
    and not 1990 as William Arnold predicted.
    This is looking at energy-in. I think earth reached its maximum output (means) a few years later, around 1998 or 1999

    Anyway, look again at my best sine wave plot for my data

    http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/

    now see:

    1900 minimum flooding – end of the warming
    1950 maximum flooding – end of cooling
    1995 minimum flooding – end of warming.
    predicted 2035-2040 – maximum flooding – end of cooling.

    Do you see the pertinent correlation with my sine wave?

    Now from the report here:

    http://wattsupwiththat.com/2008/03/16/you-ask-i-provide-november-2nd-1922-arctic-ocean-getting-warm-seals-vanish-and-icebergs-melt/

    the relevant newspaper reports severe melting of arctic ice more than two decades AFTER the end of warming 1900.

    This is how long earth stores its energy in the oceans,
    So the report of severe melting of the arctic ice in 1817, nearly two decades after the end of warming 1800 as noted from the flooding of the nile, CAN BE EXPECTED, if you allow for a general 5 year error either way, on my sinewave. It is natural, and it had nothing to do with the volcanoes..

    By 2040 everything will freeze up there again in the arctic and we will be back to where we were in 1950!

  55. Question: Is the amount of incoming or reflected heat absorbed by c02 related to the angle of incidence of such radiation? I’m not an expert in angles of incidence and radiative effects of greenhouse gases (who is), but theoretically, it might be, since with electrons, I remember vaguely from my university days, that the angle that they strike the nucleus effects both the way they are reflected and/or scattered during various experiments.

    If so, and I’m really just speculating here without knowing much about the internal physics, maybe large volcanic eruptions make the tropics and temperate regions colder because the ash reflects sunlight better where it strikes the ash layer at a more perpendicular angle, but at high latitudes because of the higher angle of incidence the net result is that it gets proportionally warmer either because incoming radiation makes it through the ash layer better, and/or the reflected heat gets absorbed better where this reflected heat strikes the ash layer at a more acute angle. ?

    This is probably incorrect, but I note that there is a difference in the way incoming and radiated heat is absorbed by c02 and other greenhouse gases, so why not with ash, or with different angles of incidence between different mediums,?. Just an idea anyway.

  56. It wouuld have been Heilpful if you had given the location of Tambora in your article.
    It certainly a puzzler. I believe Willis adressed this issue about the “year without a summer” and his article gave some interesting facts that seemed to contadict the popular conceptions.

  57. If you look at the ice core record it is hard to spot any significant problem after the 3 largest volcanoes in history. Toba (72,000 BC), Taupo (22,000 BC), Yellowstone (640,000 BC). Those were all 8 on the VEI and recent enough to have ice cores recording the temp.

    Is there a connection at all is a valid question.

  58. Here’s a link to one of the lengthier accounts of the Summer of 1816. http://www.hewitts.com/Hewitts_Home/The_Summer_that_Never_Was.html

    A couple of points. Even today, Northern New England isn’t that far from the Northern limit of agriculture. Snow in May isn’t uncommon. Even this year there were significant snowfalls in Vermont and the Adirondacks as late as May 26 (30 inches at Whiteface Mountain). Things were colder in the 18th and 19th centuries. Also 1816 was one in a string of half a dozen cold winters. e.g. the last Frost Fair on the frozen Thames River at London was held in 1814. Also, people were farming higher up on the Northern New England hills/mountains in the early 19th century than they attempt today. Finally if you look at record low temperatures at Mt Mansfield (Northwest Vermont) modern temperatures near or below freezing aren’t all that uncommon. So a bit of snow in Summer in an especially cold Summer isn’t a dramatic as it might be further South.

    It does appear that in 1816, there was probably a reservoir of cold air someplace in Northern North America and that it appears to have broken out into normally warmer areas several times — with devastating affects of crops.

  59. TRM says:

    July 8, 2013 at 9:10 am

    To answer your question, the time resolution of ice cores for the times of those eruptions is a matter of centuries. You shouldn’t expect to see an annual temperature signal in such data. Some ice cores are time adjusted by measuring the ash and sulfate concentrations that result from volcanic eruptions.

  60. I urge people to read the volume we produced of a conference on the eruption of Tambora and its impact in Ottawa in 1992 titled, “The Year without a summer?: world climate in 1816.” It is available here;

    http://www.worldcat.org/title/year-without-a-summer-world-climate-in-1816/oclc/27429039

    Chief instigator of the event was C.R. Harington head of the paleobiology division of the Museum as part of an ongoing study of climate change in Canada over the last 20,000 years. The keynote speaker was John Eddy. We also tried to get Hubert Lamb, but he was unable to attend and his assistant John Kington appeared in his place. Participants and contributors were from every continent and in a multitude of disciplines.

    Eddy was invited because, in meetings prior to the conference we were aware that global temperatures were declining in response to the Dalton Minimum, and he was writing about the temperature implications of changing solar activity.

    A major part of the conference was a workshop I organized with Cynthia Wilson in which people from all over the world were asked to bring measures of the impact on temperature and precipitation for their region. The map we produced is an insert in a pocket of the book and provides a good illustration of the changed circulation patterns, part of which were the wind and ice conditions in the Arctic as reflected in the Admiralty comments. The pattern is one of extreme Meridional flow.

  61. Good thread, lots of great input from RGB@Duke, Leif, Bob Tisdale, Caleb, Don Easterbrook, and the usual suspects.

    “CO2,” Bill_W said cryptically.
    “Yes, indeed,” I added elliptically.

    “A historical account can give you an interesting question to ask,” said Mosh-man, skeptically.
    “So can wiggle matching,” I replied tangentially.

  62. Good review of 1816..The Year without Summer in wikipedia

    https://en.wikipedia.org/wiki/Year_Without_a_Summer

    Some consequences were Turner’s paintings and Mary Shelley’s Frankenstein

    i’d suggest one of the consequences of the Lake Toba eruption, which wouldn’t show up in ice core records, was the wiping out of our homo erectus cousins in east and south Asia. This opened up the area for settlement by modern humans. Before Toba the place was full, and had been for over a million years. After Toba it was first come, first served.

  63. mosh said

    ‘historical accounts are words on a page. they are not data. you can’t take the standard deviation of words on a page. you cant go back and repeat the experiment.’

    So numbers seem to be valuable historical scientific data but sadly words always appear to you to be anecdotal.

    Can you go back to Albania on a specified day in 1895 and check that the single record they took was correct? Or, as you say perhaps you can’t go back and repeat that particular experiment.

    tonyb

  64. If the volcano produced an aerosol which resulted in abruptly cooling of the earth’s surface, perhaps the effect would be stronger over the land masses. The oceans would not cool as quickly because they are cooled by convective currents. But if additional water remained frozen on land instead of melting, could the change in flow from the Saint Lawrence Seaway change the salinity in the thermohaline? And would more salinity result in increased ice melt? Ice melt results in increasing the flow rate in the St Lawrence Seaway my something like a million gallons per second, a not inconsiderable flow rate. What if that were substantially diminished? If I get time I’ll try to quantify the effect.

  65. so, we have seen that natural forces are in play and the volcanoes do nothing or not much, except delay the cycles a little bit, maybe, CO2 does nothing at all. In fact, everybody here should know that most of the energy from the sun goes straight into the (SH) oceans and this is our energy “store”.
    Now for the real disaster:

    The Dust Bowl drought 1932-1939 was one of the worst environmental disasters of the Twentieth Century anywhere in the world. Three million people left their farms on the Great Plains during the drought and half a million migrated to other states, almost all to the West. http://www.ldeo.columbia.edu/res/div/ocp/drought/dust_storms.shtml

    I find that as we are moving into the deep end of the sine wave, there will be a standstill in the speed of warming, i.e. no acceleration and no deceleration, around the bottom, and therefore naturally, there will also be a lull in pressure difference at certain [latitudes], especially where the Dust Bowl drought took place: meaning: no wind and no weather (read: rain). However, one would apparently note this from an earlier change in direction of wind, as was the case in Joseph’s time (Gen. 41:23, 27). According to my various calculations, this disaster will start around 2019…..

    Danger from global cooling is documented and provable. It looks we have only ca. 6 “fat” years left after which there will be 7 meager years.

    http://blogs.24.com/henryp/2013/04/29/the-climate-is-changing/

  66. Don’t worry, we totally understand the climate well enough to forecast temperatures within a degree or two for the next 100 years.

  67. Having dug a little deeper into the topic, a interesting fact has turned up.
    While europe was having a “year with no summer” over in Russia they were having a hot and dry one. This been the case l think help’s to explain the cold weather in both europe and China. What seems to have happen was that they was two large blocking highs. One sat over the North Atlantic and the other over Russia. The blocking high over the North Atlantic would have forced the Polar jet up over Greenland and to come back down south again very close to Western europe. Bringing with it cold and wet weather rather like what happen in the summer of 2012. Now with there also been a blocking high over Russia then the jet would have had to push up to the north again and into the Arctic so as to flow over the top of this blocking high. Once clear of this blocking high, what seems to have happened it that the jet took a deep dive to the south over China. Bringing with it bitter winds from the north.

  68. I love farout, somewhat reasonable ideas.

    What if, volcanoes take the lower atmosphere up with the ash and such and some of it’s heat gets lost to space? The ash comes down much cooler, seeding clouds, creating low pressure systems in the tropics forcing high pressure at the poles. At the same time, a lot of heat gets lost to outer-space in one area and eventually cools the rest of the planet.

    Almost as logical as CO2 forcings governing shtuff.

    Maybe, in a thousand years or so, people will figure it out.

  69. It seems perfectly possible that ash could cause the melting of the ice sheet by increasing the albedo. Even if some of the ash was covered by snowfall, it would be exposed again once the initial snow cover melted. If the melting of arctic ice can be caused by ash from a volcanic eruption could it not also be caused by soot from coal fired power stations or diesel engines? It is well known that airborne pollutants e.g. PCBs from the northern hemisphere accumalate in the polar regions. This would mean that the decrease in summer arctic sea ice has less to do with climate change and is instead correlated with the rapid industrialisation of China and India over the past 2 decades, most of which has been feulled with coal and dirty technology. Unfortunately this could mean that the ice will continue to melt faster than 20 years ago whatever happens to the temperature (and give the alarmists something to bang on about even if global temperatures continue to decline).
    The above is pure speculation, does anyone have any data to try and prove or disprove it?

  70. Adding to my first post in this thread, I have performed experiments with water vapor and high potential electrostatic fields. The high potential electrostatic fields definitely have an effect on water vapor through the force of diamagnetism.

    As for electrical discharges of the ionosphere to ground, we see these from time to time when dusty asteroids and comets enter the atmosphere and release a tremendous amount of energy. This energy appears to be misinterpreted by the mainstream as frictional heating. Although frictional heating does occur, it is likely not the entire physical explanation for large explosions such as occurred over Russia in 1906 and earlier this year.

    Lightning is frequently observed in volcanic eruptions. This is due to potential differences in the volcanic dust, however, the dust does show conductivity as observed by the behavior of the electrical discharges. It is not unlikely that a dust plume of super heated dust reaching high into the ionosphere could cause a major electrical discharge of the ionosphere.

    Recently, the Earth’s ionosphere has been observed to be 200 km lower than usual. This corresponds with the weaker solar activity and it also corresponds to a weaker electric field around the Earth. The weaker lower electric field of the Earth will no longer hold the cold air within the Polar Jet Stream, and the other Jet Streams of the planet will also find different paths.

    When the Polar Jet Stream loses its boundary, the centripetal force carries it south. When the air is displaced to the south, something has to fill the vacuum and it comes up from the Eastern North Pacific and Asia and thus melts the Bering Sea while bringing warmer than usual temperatures to Alaska.

  71. In the polar regions atmospheric ash absorption would introduce heating at the surface since that light would have been reflected back to space.

    In non polar regions which have a lower albedo , the increased atmospheric absorption is less efficient than absorption at the surface, and increased reflection causes cooling.

  72. A couple of points.

    It’s not generally appreciated that around the summer solstice, large areas north of the Arctic Circle and south of the Antarctic Circle get more solar radiation (ignoring clouds) on a daily basis than anywhere else on Earth. Small albedo changes will have large effects on the amount of solar energy ‘captured’ at the surface.

    Despite what you may hear, polar sea ice melts predominately at the surface from solar radiation. Thus, even if the Tambora dust was buried beneath snow (and likely mostly embedded in the snow), as the surface melt progresses, the embedded dust will accumulate at the surface, decreasing albedo, and causing a larger than normal melt.

  73. FWIW, Manhattan has a land area of 33.77 sq. miles. The ash from the 1815 Tambora eruption would cover Manhattan to a depth of a mile.

  74. A bit O/T but worth keeping handy for the September minimum in Arctic sea ice extent.

    Abstract
    The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism

    The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for the area 60°–90°N amounted to some 1.7°C…..
    dx.doi.org/10.1175/1520-0442(2004)017%3C4045:TETWIT%3E2.0.CO;2

    Abstract
    The regime shift of the 1920s and 1930s in the North Atlantic

    During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish. Boreal species of fish such as cod, haddock and herring expanded farther north while colder-water species such as capelin and polar cod retreated northward. The maximum recorded movement involved cod, which spread approximately 1200 km northward along West Greenland……
    dx.doi.org/10.1016/j.pocean.2006.02.011

    Monthly Weather Review October 10, 1922.
    The Arctic seems to be warming up. Reports from fishermen, seal hunters, and explores who sail the seas about Spitsbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures in that part of the earth’s surface….

    In August, 1922, the Norwegian Department of Commerce sent an expedition to Spitsbergen and Bear Island under Dr. Adolf Hoel, lecturer on geology at the University of Christiania. The oceanographic observations (reported that) Ice conditions were exceptional. In fact, so little ice has never before been noted. The expedition all but established a record, sailing as far north as 81o 29′ in ice-free water. This is the farthest north ever reached with modern oceanographic apparatus…..”
    docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

    H.H. Lamb1965
    The early medieval warm epoch and its sequel

    “The Arctic pack ice was so much less extensive than in recent times that appearances of drift ice near Iceland and Greenland south of 70[deg] N, were apparently rare in the 10th century and unknown between 1020 and 1194, when a rapid increase of frequency caused a permanent change of shipping routes. Brooks suggested that the Arctic Ocean became ice-free in the summers of this epoch, as in the Climatic Optimum; but it seems more probable that there was some ‘permanent’ ice, limited to areas north of 80[deg] N….”
    Elsevier Publishing Company
    Palaeogeography, Palaeoclimatology, Palaeoecology, 1:1965, p. 15-16

    Abstract
    The 15th century Arctic warming in coupled model simulations with data assimilation

    … Available observational data, proxy-based reconstructions and our model results suggest that the Arctic climate is characterized by substantial variations in surface temperature over the past millennium. Though the most recent decades are likely to be the warmest of the past millennium, we find evidence for substantial past warming episodes in the Arctic. In particular, our model reconstructions show a prominent warm event during the period 1470–1520. This warm period is likely related to the internal variability of the climate system, that is the variability present in the absence of any change in external forcing….
    doi:10.5194/cp-5-389-2009

  75. This would mean that the decrease in summer arctic sea ice has less to do with climate change and is instead correlated with the rapid industrialisation of China and India over the past 2 decades, most of which has been feulled with coal and dirty technology.

    I attribute it mostly to the shutting down of Soviet era heavily aerosol and black carbon polluting industries around the time of the Russian financial crisis in 1988.

    There are multiple pieces of evidence that point to this, particularly most of new ice free areas in summer are on the Russian side of the Arctic Ocean.

    Briefly, the aerosols seeded clouds, and the black carbon was deposited on and became embedded in multi-year sea ice. After 1988, as aerosol seeded clouds decreased, solar insolation increased and surface melt of the ice increased. Resulting in embedded black carbon accumulating at the surface, and causing the progressively increasing summer melt we see after 1988.

    If I am right, we have seen the peak of the summer ice melt as most the ice with embedded black carbon has already melted out. Although the decreased in aerosol seeded clouds continues.

  76. Should we believe Mann on this? Where actual data is available his reconstructions don’t even correlate as well to the actual data as random numbers do.

  77. What I understood from postings by Piers Corbyn is this: The Arctic waters are connected to the great oceans. The entrance on the Atlantic side is wide, but on the other side, the Bering Sea, it is narrow. When the earth is cooling, the Bering Sea is full of ice, like it is now in recent years. Water coming from the Atlantic can not flow further to the Pacific side, because the frozen Bering Sea blocks that current. Instead, the warmer water from the Atlantic makes circles in the Arctic Sea and it all flows back into the Atlantic Ocean, while in warmer years a part of that water would flow into the Bering Sea. This also explains why in colder years the ice on the Atlantic side of the Arctic Sea, specially in the so-called Gore-zone, is getting thinner. So the mistake the scientists of those days made was that they saw less ice in the Atlantic side of the Arctic Sea, but they didn’t know what the condition was of the ice on the side of the Bering Sea, which probably was frozen.

  78. A few comments have alluded to the possibility of the 1998 super-El-Nino being a rebound to the 1991 Pinatubo volcano event. Take a look at the Google spreadsheet at https://docs.google.com/spreadsheet/ccc?key=0AnTohu4oFUbcdEgzTkpEYTAwN1BiXzJXMXZ5RVJiOUE#gid=17 The graph on tab “12mo1850# shows 12-month running means. HadCRUT3 and HadCRUT4 show a super-El-Nino spike in the late 1870#s.

    Look at tab “temp_data”. Column B is HadCRUT3 monthly anomaly (versus 1961-1990 normals), and column C is HadCRUT4. HadCRUT3 shows a positive anomaly from 1877.667 (August 1877) through 1878.333 (April 1878). HadCRUT4 is positive July 1877 through April 1878. HadCRUT (3 and 4) were averaging around -0.3 in the preceding 15 years, so that was a major jump. Any ideas about what this could’ve been a rebound from?

  79. fhhaynie says: July 8, 2013 at 10:21 am

    > TRM says: July 8, 2013 at 9:10 am

    To answer your question, the time resolution of ice cores for the times of those eruptions is a matter of centuries. You shouldn’t expect to see an annual temperature signal in such data. Some ice cores are time adjusted by measuring the ash and sulfate concentrations that result from volcanic eruptions.

    Ah that is interesting. Thanks. I learn so much from this site.

    • lsvalgaard says:

      July 8, 2013 at 5:44 pm

      I’m talking about the time resolution for the temperature proxies like 18O index: not the adjustment of the depth scale time using ash and sulfate concentrations.

  80. Most of the decade of the 1810’s was cold. The great Climatologist Helmut Landsberg considered the year 1812 to be the coldest in northern hemisphere instrumental records.

  81. Taxed says:
    July 8, 2013 at 1:05 pm
    Having dug a little deeper into the topic, a interesting fact has turned up.
    While europe was having a “year with no summer” over in Russia they were having a hot and dry one. This been the case l think help’s to explain the cold weather in both europe and China. What seems to have happen was that they was two large blocking highs. One sat over the North Atlantic and the other over Russia. The blocking high over the North Atlantic would have forced the Polar jet up over Greenland and to come back down south again very close to Western europe. Bringing with it cold and wet weather rather like what happen in the summer of 2012. Now with there also been a blocking high over Russia then the jet would have had to push up to the north again and into the Arctic so as to flow over the top of this blocking high. Once clear of this blocking high, what seems to have happened it that the jet took a deep dive to the south over China. Bringing with it bitter winds from the north.
    _________________________________
    Taxed as above has pointed to a phenomenon I was wondering about, the shifting of the polar jets following the injection of very large amounts of dust and gas up to 40 kms high into the stratosphere from the Tambora eruption.

    Tambora lies quite close to the equator where the solar energy inflows are always highest.
    As the global temperatures decreased by large amounts leading to the cold years following the eruption the only reasonable explanation is that the injection of dust and gases from the eruption into the stratosphere were responsible for this cooling.

    I would suggest the following mechanism for both the lower latitude cooling and the polar warming events following the Tambora eruption ,

    The solar energy inflows during this period would have remained constant and no more than the normal variations so as this solar energy, the surface heating energy from the sun was not getting through the stratospheric dust and gas veil to the surface and is not accounted for elsewhere around the low latitudes, it would seem very likely that the stratospheric dust and gases from Tambora eruption were both reflecting some incoming solar energy but most likely due to their dark colouring, were also absorbing a great deal of this formerly surface destined solar energy spectrum.
    The consequences would have been a steady build up in and a long lasting stratospheric warming event as the dust and gas veil spread around the globe and a cooling of the surface below the stratospheric dust cloud and gas veil.
    The solar energy budget was just reallocated between the absorption of solar energy by Tambora’s stratospheric dust and gas veil, some reflectance of that solar energy by that dust and gas veil and and the reduced solar induced surface heating due to the shading by the dust and gas veil

    The consequent substantial warming of the dust and gases and therefore the stratosphere would have produced effects almost identical to but a lot longer lasting to the Sudden Stratospheric Warming events which are now known to abruptly shift the polar jets locations and change their flow structures leading to extreme cold outbursts in some lower latitude near polar regions and extreme warming in higher latitudes including the actual polar regions.

    With the long lasting dust and gas veils from the Tambora eruption this stratospheric warming effect would have had a slow build up relative to the rate of the onset of the SSW events and a much longer wind down as the stratospheric dust and gas veil slowly dissipated over a period of years.

    As “Taxed” above points out , there were areas of extreme warmth in northern regions as well as extreme cold in other regions, all of which point to a major and in this case, long lasting shift in the polar jets akin to a SSW event.
    But this time, created by the interception of incoming solar energy by the Tambora created stratospheric dust and gas clouds and the consequent heating of those dust and gas clouds leading to the creation of a stratospheric warming event of years long duration and the consequent shifting of the polar jets which allied with the reduction of solar heating of the surface due to the shading effects of the dust clouds would have led to extremely cold temperatures in some regions .
    A secondary effect would have been for the polar jets to trap and redirect some of this dust around some areas allowing greater solar surface heating which would have reinforced any warming in those other areas as per Taxed post above.

  82. I’m back. 103 comments…..sheesh!

    I spent the afternoon studying the connection between near record rainfall and busted belts on old, lumbering 1985 rider mowers. The rain makes mowing impossible even as the grass grows like crazy, so that when you do mow the blades get stressed in deep lushness, and in 90 degree temperatures the Lord-knows-how-old belt disintegrates into small chunks of hard rubber.

    The local small-engine-repair guy has a two week backlog of work, but was kind enough to help me locate a belt and give me instructions about how to do the job. After a fair amount of sweating and swearing I was done, and the blame thing actually works!

    It wasn’t the easiest job, and success has boosted my ego no end. I feel I can handle anything, and am ready to take on chaotic systems.

    A couple of commenters sounded as if they felt that, because it is difficult to see a volcano-effect, there must be no effect. To me this is a bit like saying a thousand atomic bombs going off has no effect. Of course it has an effect.

    After Pinetubo I could lift my fist and cover the sun in a way that allowed me to see the “rays” without being blinded by the actual sun. The “rays” were much longer than they are now, as if the sun was shining through dirty glass. Also my tomatoes stayed green. So don’t tell me volcanoes “have no effect.”

    The problem is we don’t really understand the oceanic cycles, even without volcanoes. We have all these wonderful new satellites, that were not around when I was a kid, giving us amazing insights, but unfortunately politicians are demanding certain results, and not allowing scientists to do what they do best, which is not so much to create, as to observe. Tisdale sets a good example, for he simply reports what he observes. Some others do the same, but they almost seem apologetic about it, as if they feel guilty for sneaking some real science in.

    Bob Tisdale gave me one link which suggests volcanoes prompt a zonal flow, whereas Dr. Tim Ball describes a wonderful meeting of minds (I’ve got to get that book) which suggests volcanoes prompt a meridional flow. (“Meridional” sounds so much better than my word “loopy.”) This may prompt some to throw up their hands in despair and quit.

    Don’t do it. Don’t give up the ship. I wanted to quit today, lieing all sweaty in the grass with dratted bugs crawling all over me, for it seemed scientifically impossible to remove the old mower belt, let alone put on a new one, however by gritting my logic I eventually figured out all the pulleys and shields and nuts and bolts.

    In the same way we can figure out this climate system, even if it is chaotic. After all, it is just so many actions and reactions. However it is a bit like a tangled fishing line with lots of loops. You want to just whip out a knife and cut the snarl away. However pretend you have no knife. It is actually quite possible, and very gratifying, to untangle the mess. (I take eight small children fishing on a regular basis, so I’m an expert on untangling fishing lines, if nothing else.)

    One insight, which I thought was good, was the comment about how the ash would effect the land immediately, but take longer to effect the oceans, which in a sense have momentum and “remember” the pre-volcano situation.

    Bob Tisdale’s observations, (buy his book,) give us inklings of the pre-volcano pattern, though we still don’t understand all the parts. It is a bit like watching a child levitate back and forth in mid air, without knowledge of the seat, ropes, and tree-branch overhead, which form the swing the kid’s upon. However we do glimpse a sort of pendulum, swinging back and forth like clockwork.

    OK. The pre-volcano situation is like a child on a swing, and the oceans are the boss, and in control of the winds. Then a volcano goes off. Suddenly there is a new boss in control of the winds. To continue my analogy, it is as if you are pushing a child on a swing, and suddenly this weirdo comes in from the side and gives the kid a push. Obviously the pendulum is going to go all out of whack.

    In other words, maybe the pattern goes zonal, and then meridional. The initial effect of ash is to make the air disobey the sea, and abruptly be zonal, which gives is a warm winter after the volcanic eruption. (A chance to get ready.) However this knocks the sea’s regular pattern out of whack, which then effects the atmosphere to become loopy, (excuse me…I mean meridional.)
    Then you have heat waves in Alaska and frosts in Florida.

    That’s the idea bopping about my brains tonight, (perhaps due to too much time under a hot sun, today.)

    However I feel it is also important to consider where you are, in the pre-volcano cycle, when the volcano blows. If the pendulum is going one way, about to enter a La Nina, the effect is likely to be quite different from when the pendulum is headed the other way, about to enter a La Nina.

    And considering we don’t even fully understand the pre-volcano cycle yet, I sure do wish the blasted politicians would back off, and quit demanding results when we’ve only just started.

    .

  83. Correction to above comment: “If the pendulum is going one way, about to enter a La Nina, the effect is likely to be quite different from when the pendulum is headed the other way, about to enter a EL NINO.”

    It’s late. Time for this boy to hit the sack. Heartfelt thanks to all who commented.

  84. Caleb says:
    July 8, 2013 at 8:21 pm “After Pinetubo I could lift my fist and cover the sun in a way that allowed me to see the “rays” without being blinded by the actual sun. The “rays” were much longer than they are now, as if the sun was shining through dirty glass. Also my tomatoes stayed green. So don’t tell me volcanoes “have no effect.””

    We had the most amazing red orange sunsets after Pinetubo. And for the pilots in the group, we noticed a pronounced haze that whitened the sky from it’s normally deep blue. Then there was the nasty winter that followed. Coincidence?

  85. fhhaynie says:
    July 9, 2013 at 5:59 am
    That’s layer counting, not temperature proxie data like 18O.
    Look at Figure 3 of http://epic.awi.de/12532/1/Ras2005a.pdf
    “Example of 1.2 meter of GRIP data and annual layer markings (grey vertical bars) from
    about 8.8 ka b2k. The annual layers are identified as matching pairs of spring and summer indicators:
    [...] In this section the annual layer identification procedure is supported by high-resolution δ18O data, corrected for diffusion.”

    • Lief,
      Good illustration. At 8.8ka bk2 the actual 18O index has a very low amplitude. As you go back further in time, the amplitude decreases. What would you expect the amplitude to be at 22ka or 480ka? Adjusting for diffusion on an annual basis is speculative for these times. It becomes an artificial adjustment.

  86. fhhaynie says:
    July 9, 2013 at 7:35 am
    Adjusting for diffusion on an annual basis is speculative for these times. It becomes an artificial adjustment.
    Possibly, but there is a lot of speculation already. You are arguing that a climate signal should not be expected for the Toba event and since none is observed we cannot rule out that there was a Toba-induced climate effect. Also possible.

    • I agree. There must have been an effect on climate temperature, but the ice core proxie temperature data does not have the resolution to show a one or two year change for those old eruptions. We could speculate that what the temperature change rate would be for those old eruptions and back calculate what to expect in a diffusion “corrected” proxie record.

  87. Just follow the natural cycles by the sun clearly evident from looking at maximum temps. Volcanic eruptions may delay the sun a bit, short time, but not by much….

  88. All such reductions In sea ice extent will be during stronger negative NAO/AO conditions, it would have happened without any volcano. 1816 was well placed at the peak of solar cycle 6, at the Ap index drop out that happens in many solar cycles at maximum:

    http://www.solen.info/solar/cycl6.html

  89. Subsequent to the Royal Society meeting in the fall of 1816 the Royal Navy sent an expedition to Spitsbergen to check out the status of the ice. They found that by then the ice was back to normal and the ships got trapped in ice in July 1817 and were forced to abandon one of their ships in order to get back to Britain. So whatever happened in the Arctic in 1816 it was short-lived.

  90. lsvalgaard says:
    “Except that Ap is not correlated with temperatures, e.g. http://www.leif.org/research/Ap-GCR-TSI-Temp-1978-2012.png

    There should be plenty of inverse correlation with global temperatures, as your graph shows, because of ENSO type response. Only and temperatres at higher latitudes will display a direct correlation. Interstingly there were La Nina conditions between late 1815 and mid 1816, which does not suggest strong cooling from Tambora.

  91. @thingodonta July 8, 2013 at 3:46 am:
    “…One point, the ash apparently went towards the N/NW, which winds occur in the dry season from ~April to ~October. Sicne Tambora is just south of the equator (and not far from where I work in East Nusa Tengarra), that’s a long way to the north pole.”

    This is the same argument I used in the 1980s about CFCs produced in the cities in the northern hemisphere supposedly then producing the Ozone Hole at the South Pole: That’s a long way to the South Pole.

    It gets even stranger when one considers that those same cities where the CFCs were being released had ozone alerts.

    Operative questions then become:

    Why didn’t the CFCs react with the ozone in those cities up north?

    How did the CFCs get all the way to the South Pole before reacting with ozone somewhere in between?

    How did CFCs cross all these atmospheric systems: The north Mid-latitude cell, the north Hadley cell, the Intertropical Convergence Zone, the south Hadley cell, and the south Mid-latitude cell? All before finally taking root in the South Polar region, there to gobble and gobble and gobble ozone?

    But maybe the biggest question is: What mechanism carried the CFCs on a beeline to the South Pole? No vacations in Bermuda, no stop-overs in Bali, no weekends in Rio. Just hop the Express Train to Penguinsville.

    Yep, that’s a long way to the South Pole.

  92. Leif, your first link does show inverse correlation, the yearly data is too crude to see it well in places though, like in 1997/98. I still say the critical factor for low sea ice extent is negative AO/NAO, which has happened regularly without any help from volcanic eruptions.

  93. Ulric Lyons says:
    July 9, 2013 at 7:16 pm
    Leif, your first link does show inverse correlation, the yearly data is too crude to see it well in places though
    You can’t have it both ways, if the data is too crude you cannot use it. Also you didn’t like the global data, so we use CET instead. Since there is a strong seasonal variation of CET but not of Ap, one has to do one [or both] of two things, either compute running means over the year of the daily [or monthly] data and compare those with Ap or work with the CET anomalies [that removes the seasonal variation]. In either case one can see that there is no correlation whatsoever: http://www.leif.org/research/Ap-CET-Uncorrelated.png or http://www.leif.org/research/Correlation-Ap-Temp-Not.png
    I think we have had this crop up before, so you are going in circles. Ap is not correlated with temperatures.

    I still say the critical factor for low sea ice extent is negative AO/NAO, which has happened regularly without any help from volcanic eruptions.
    This has nothing to do with Ap and sea ice extent is not correlated with AO/NAO on a daily or monthly basis. So this is a strawman thrown in to complicate matters.

  94. RE: Phil. says:
    July 9, 2013 at 9:36 am

    Hi Phil. It’s getting to be that time of year. I’ll be expecting interesting input from you as the minimum-sea-ice posts appear.

    I’ve been doing some research, with all the links in this post. Apparently the sea ice went through some wild swings after the “mystery volcano” and Tambora. Besides the refreeze you mention there were two others, but also times of decreased ice.

    “The uncharted coastline of east Greenland became clear of ice around 1820, and in 1822 Scoresby, in the midst of an arduous whaling voyage, sailed along some 400 miles of this inhospitable landscape, charting it, and naming point as he went in honour of scientific and other friends, chief of which was Scoresby Sound, named for his father. Almost all his place names survive today.”

    It looks like Steve Goddard got researching as well. How many Manhattans is a 18000 square mile discharge of ice? I wonder if that was the same ice that was amazing people right into August on the north coast of Ireland at that time?

    There must have been a howling north wind in the Fram Straits to push out all that ice. That gets me thinking about Dr. Tim Ball’s assertion that the jet stream was very meridional.

    My brains are sort of smoking with all the information people have shared. I awoke at three AM with odd, dream-like thoughts of lightning discharging down the smoke of Volcano’s. It made perfect sense at the time, but faded by dawn. My mind needs to incubate all the data before new ideas hatch. Unfortunately some think that just because I fixed the mower, I should mow.

    Thinking about all this stuff, I’ll probably drive into the pond. Then they’ll be sorry.

  95. Leif,
    There is very regular correlation between negative AO/NAO and less sea ice extent, that is most certain, and is the pivotal issue. The correlation of CET with Ap is there in the short term deviations from normals, though I would of course make more recent comparisons directly with the solar wind speed rather than the Ap index.

  96. Ulric Lyons says:
    July 10, 2013 at 6:32 am
    There is very regular correlation between negative AO/NAO and less sea ice extent, that is most certain, and is the pivotal issue.
    On what time scale? days? month? years? Show the correlation.

    The correlation of CET with Ap is there in the short term deviations from normals, though I would of course make more recent comparisons directly with the solar wind speed rather than the Ap index.
    I have just shown you that there is no such correlation.

  97. @Leif
    Weekly to monthly with a small lag. Every one of the accounts of greatly reduced sea ice over the last couple of hundred years had strong negative AO/NAO conditions. As have the recent lows in summer ice extent in 2007 and 2012. The acceleration of ice extent reduction since 1998 is exactly coincident with an increase in negative AO/NAO conditions. You will not find such regular correlations with stratospheric volcanic aerosols and reduced ice extent.
    If I suggest you look at something through my magnifying glass, you are bound not to see it through your filtered telescope, re. your 1 year running mean.

  98. Ulric Lyons says:
    July 10, 2013 at 7:10 am
    Weekly to monthly with a small lag. Every one of the accounts of greatly reduced sea ice over the last couple of hundred years had strong negative AO/NAO conditions.
    You mean the summer ice was reduced? Show some evidence, perhaps from a couple of hundreds years ago. Re Ap, on a monthly scale there is no correlation with CET anomalies: http://www.leif.org/research/Correlation-Ap-Temp-Not.png

  99. Leif,
    Were you doubting the validity of the reports of reduced ice extent from 1816 in this post?

  100. Ulric Lyons says:
    July 10, 2013 at 7:31 am
    Were you doubting the validity of the reports of reduced ice extent from 1816 in this post?
    I would like you to produce evidence that strong negative AO/NAO preceded the loss by a few weeks with a small lag.

  101. Leif, you know that we do not have such data for 1816/18, modern data shows this lag. Where did you get the few weeks from? creating a new arbitrary straw man measure yet again that I made no mention of.

  102. Ulric Lyons says:
    July 10, 2013 at 7:57 am
    Leif, you know that we do not have such data for 1816/18
    Ulric Lyons says: July 10, 2013 at 7:10 am: Every one of the accounts of greatly reduced sea ice over the last couple of hundred years had strong negative AO/NAO conditions

    Where did you get the few weeks from?
    Ulric Lyons says: July 10, 2013 at 7:10 am: Weekly to monthly
    That is a ‘few weeks’ as a month is 4 weeks [approximately] and 1 to 4 weeks is a few weeks.

  103. Ulric Lyons says:
    July 10, 2013 at 8:10 am
    Leif, you confused the correlation scale with the lag time.
    I asked toy what the correlation time scale was and you answered ‘weekly to monthly’. What is to confuse about that? Also: the ‘small lag’ seems to be smaller than the correlation time, but is not what I asked for. So again: I would like you to produce evidence that strong negative AO/NAO preceded the loss by a few weeks with a small lag in 1816 as you claimed that “Every one of the accounts of greatly reduced sea ice over the last couple of hundred years had strong negative AO/NAO conditions”

  104. No it precedes it by the length of the lag. I never said anything about it preceding by a few weeks, that,s your continued confusion between scale and lag. For 1816-18 I have only seen monthly NAO.

  105. Ulric Lyons says:
    July 10, 2013 at 8:41 am
    No it precedes it by the length of the lag. I never said anything about it preceding by a few weeks
    I asked what the time scale of the correlation was, and you answered “Weekly to monthly with a small lag”. Since I didn’t ask about the lag, your answer seems to imply that the time scale for the correlation is ‘Weekly to Months’. What is to confuse about that?
    For 1816-18 I have only seen monthly NAO.
    Ulric Lyons says: July 10, 2013 at 7:57 am: “you know that we do not have such data for 1816/18
    The ‘lag’ is your new straw man.

  106. Ulric Lyons says:
    July 11, 2013 at 6:14 am
    the lag is visible in the modern daily data, it appears to be around one week.
    Ok, so let us pursue your lag straw man. It is a bit strange that the lag should be one week as the summertime sea ice concentration is strongly correlated with the AO index for the previous winter.

  107. Leif: Yes inter-seasonal scale hysteresis is another factor, but there is no need to confuse that with short term lags.

  108. Ulric Lyons says:
    July 11, 2013 at 8:44 am
    Yes inter-seasonal scale hysteresis is another factor, but there is no need to confuse that with short term lags.
    There is no short-term lag as the correlation is only for the seasonal effects.

  109. henry says
    my investigations show most (maxima) heat going into the sh oceans and ending up as (means) heat going into nh continents

    should read
    my investigations show most (maxima) heat going into the sh oceans and ending up as (means) heat going onto nh continents

  110. lsvalgaard says:
    “There is no short-term lag as the correlation is only for the seasonal effects.”

    There is often a short term lag between say the NAO going negative (with the jet stream moving south and lower CET), and a decrease in sea ice extent. An example is around April 12th 2008:

    where the decline in ice extent is about a week after the drop in daily CET.

  111. Ulric Lyons says:
    July 11, 2013 at 5:02 pm
    There is often a short term lag between say the NAO going negative (with the jet stream moving south and lower CET), and a decrease in sea ice extent. An example is around April 12th 2008
    As you can see from your figure that is the only such excursion in eight years and thus means nothing and the ‘often’ is then clearly not true.

  112. @lsvalgaard

    There are many other examples there, and also the opposite, where ice extent increases with a positive AO/NAO.

  113. Ulric Lyons says:
    July 11, 2013 at 7:31 pm
    There are many other examples there, and also the opposite, where ice extent increases with a positive AO/NAO.
    I don’t see more than one that looks significant. Mark the ‘many’ others ones you think you see.

  114. Ulric Lyons says:
    July 11, 2013 at 7:31 pm
    There are many other examples there, and also the opposite, where ice extent increases with a positive AO/NAO.
    On longer time scales it is established http://www.terrapub.co.jp/journals/JO/pdf/6303/63030505.pdf that
    “wind forcing is a major driving force of Arctic sea-ice motion. The correlation between AO indexes and the principal components of mode-one of PCA of monthly Arctic sea-ice motion is found to be low but statistically significant”. So no surprises there. Having thus disposed of your straw man, we can return to the question of Ap [or solar wind speed] and AO. Show that there is a correlation.

  115. Leif Svalgaard says:

    “On longer time scales it is established http://www.terrapub.co.jp/journals/JO/pdf/6303/63030505.pdf that..”

    The correlation coefficient would be improved by reducing the scale, the Dec/Jan/Feb mean is pretty crude. Take Feb 2012 for UK/Euro, the first half was bitter cold, the second half well above normal, and the month around average. So major features get lost even at a monthly mean. The ice extent recovers from the 4th week of Feb 2012, about a week after the Euro thaw from mid Feb:

  116. Ulric Lyons says:
    July 12, 2013 at 6:17 am
    The ice extent recovers from the 4th week of Feb 2012, about a week after the Euro thaw from mid Feb:
    You really cannot conclude anything from such rare, cherry-picked examples that are just wiggles among so many other ones. ‘Euro thaw’? what was AO?

  117. Ulric Lyons says:
    July 12, 2013 at 4:58 pm
    With enough examples per year it would not be cherry picking.
    The correct and easy way of analyzing this is called a ‘superposed epoch analysis’. You make a list of ‘key’ times, e.g. of when AO went negative, then line up the ice record on those times and compute the average for the key time, the day before and after, two days before and after, etc [up to, say, a month] and an error bar. Then another set of times when AO went positive and do the analysis with those. Make up those two list and I’ll help you with the superposed epoch analysis.

Comments are closed.