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.”
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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.
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.
A bad summer can be cold but also overcast and wet. I wonder are volcanos at all linked with the latter two?
Paragraph 6: ‘intriguing’, not ‘intreauging’
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 .
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.
corr.
1. reduced cloud cover (less tropical storms) enables ocean surface to catche a higher percentage of the reduced solar available
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?
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).
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.
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.
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.
http://en.wikipedia.org/wiki/File:Greenland_sulfate.png
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!
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!” 😉
A comment of mine seems to be spam-filtered.
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.
http://en.wikipedia.org/wiki/File:Greenland_sulfate.png
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!
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.
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…
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.
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
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.
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.
Correction: It should have read ‘atmospheric’, not ‘celestial’, even though the observer at the time couldn’t necessarily distinguish the two.
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.
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.
“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 @ur momisugly 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.