Icelandic volcano exonerated for harsh winter of 1783–1784

File:Laki fissure (3).jpg

The central fissure of Laki volcano, Iceland

From AGU’s Geophysical Research Letters:

 

In June 1783 the Laki volcano in Iceland began to erupt, and continued erupting for months, causing a major environmental disaster. The eruption spewed out toxic sulfuric acid aerosols, which spread over northern latitudes and caused thousands of deaths. That summer, there were heat waves, widespread famines, crop failures, and livestock losses. During the following winter, temperatures in Europe were about 2 degrees Celsius (3.6 degrees Fahrenheit) below average for the late 1700s; the winter was also one of the most severe of the past 500 years in eastern North America. The Laki eruption has been blamed for the anomalously cold winter of 1783–1784.

However, a new study by D’Arrigo et al. challenges that interpretation, suggesting instead that the cold winter was caused not by the Laki eruption but by an unusual combination of a negative phase of the North Atlantic Oscillation (NAO) and an El Niño–Southern Oscillation (ENSO) warm phase. The authors analyzed 600-year tree ring reconstructions to show that the NAO and ENSO indices were similar to their values during the 2009–2010 winter, which, like the 1783–1784 winter, was unusually cold and snowy across western Europe and eastern North America. The 2009–2010 winter has been shown to be attributable to NAO and ENSO conditions (and their combined effect), not to greenhouse gas forcing or other causes. The authors add that other data and climate simulations support their hypothesis that this natural NAO/ENSO variability, not the Laki eruption, caused the cold winter of 1783–1784.

Source:

Geophysical Research Letters, (GRL) paper 10.1029/2011GL046696, 2011

Title:

“The anomalous winter of 1783–1784: Was the Laki eruption or an analog of the 2009–2010 winter to blame?”

Authors:

Rosanne D’Arrigo, Richard Seager, Jason E. Smerdon, and Edward R. Cook
Lamont-Doherty Earth Observatory, Earth Institute at Columbia University, Palisades, New York, USA;
Allegra N. LeGrande
NASA Goddard Institute for Space Studies, New York, New York, USA.
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41 thoughts on “Icelandic volcano exonerated for harsh winter of 1783–1784

  1. Surely the recent snowy winter weather was due to the Eyjafjallajökull erruption in Spring 2010! Icelandic volacnic eruptions seem to be linked to snowy winters!

  2. “Exonerated?” Maybe, maybe not. We have here two phenomena – the Laki eruption and the NAO/ENSO circumstances. The correlations suggest both as candidate causes.
    So this could be a case of “And” rather than “Or”.

  3. Proxies.Tree rings. Reconstructions. Does any of this sound familiar? If you have a broken hockey stick, you are not allowed to hand pass the puck. I am rapidly approaching the point where, at least on the subject of climate, I do not believe anybody about anything. To paraphrase: Weather happens! Now can we get on with our lives?

  4. “The authors analyzed… tree ring reconstructions”
    A phrase that always sends chills up my spine.

  5. Despite large volumes of ash being sent into the atmosphere this eruption was probably too small to have a measurable effect on the winter. There are other effects that have a greater input which would be responsible.

  6. “a combination of a negative phase of the North Atlantic Oscillation (NAO) and an El Niño–Southern Oscillation (ENSO) warm phase.”
    I’ve been saying for some years that jetstream latitudinal positioning and/or degree of meridionality is a consequence of an interaction between top down solar effects on the size of the polar air masses and bottom up oceanic effects on the width of the tropics.
    Sometimes they are in phase as during the late 20th century when both features combined to produce poleward jets.
    Sometimes they are out of phase when both features oppose one another to fight it out over the mid latitudes as in the events detailed in that paper.
    In 1783 there was a historic low in solar activity hence the highly negative AO/NAO and it bumped up against warm SSTs apparently.
    The recent low solar activity also gave a strongly negative AO but since we are now in a cool PDO phase it was not opposed by warm SSTs as strongly as in 1783.
    Nonetheless we did see some record snows and low temperatures with a colder UK December than almost all others back to 1650 or thereabouts.
    Lots of strong correlations turning up, persuasive as to causative significance and in accordance with my climate model.

  7. OT but important BLACKBOARD, Lucia Lilligjren is not respecting anonymity. Some person has posted all my personal details (real name, job etc) on her site and she has allowed it. Be very, very weary of posting there.

  8. Quote “The 2009–2010 winter has been shown to be attributable to NAO and ENSO conditions (and their combined effect), not to greenhouse gas forcing or other causes. ”
    Heretics, burn the heretics……sarc off.
    Refreashing to see that a study not trying to link in AGW to the cold winter for a change and finding a possible natural cause!!

  9. Take that back my name has just been removed from the Blackboard she just done the right thing. You can visit her site with assurances me thinks LOL

  10. Does not compute. In 1783-84 there were ice floes in the Gulf of Mexico, you could ice-skate in Charleston, SC, the Mississippi froze over at New Orleans. It snowed a lot and was cold in 2009-2010; that’s all I recall. Yet 2009-10 had the number 1 paleo-index for the NAO over #2 1783-84? Wouldn’t that mean some other explanation (like, say… Laki) IS a likely candidate for the huge differences between the two winters? Sure, the NAO made it worse than it would have been, but….ice floes in the Gulf of Mexico? Isn’t that rare?

  11. We always see things in black and white, it has to be A or B. But why can’t it be a combination? Pinatubo dropped world temps by a degree for a year and a half, not from the ash but from sulfate driving to the top of the stratosphere.
    So why shouldn’t we think that the natural phenomenon seen by the authors (and perhaps due in part to low solar activity, as suggested by Stephen Wilde) be responsible for some of the cooling, and sulfate from the volcano responsible for the rest?

  12. 1783 may have been a solar minimum but certainly not a grand minimum. I would wonder how accurately we can determine atmospheric oscillations of time periods so long ago?
    But one severe winter in NE USA certainly could be a product of low EUV (neg AO/NAO) which coincides with a strong El Nino that can happen even during a neg phase of the PDO as seen in 2009. The ENSO factor being a passenger while the jet streams do their thing. Interestingly we now have a strongly positive AO and a strongly neg AAO which is the complete opposite to last December, but the jet streams although suppressed a tad are still showing major disturbance. The polar vortex perhaps just being one player in the game?

  13. Maybe, just keeping an open mind here, there is a relationship between the oscillation and the likelihood of eruption. Maybe they go hand in hand?…sometimes?
    In both cases cited, there were oscillations and eruptions. Maybe the severe weather needs both.

  14. Nir Shaviv’s presentation on the earlier thread mentioned that GCM’s were oversensitive to forcings, and he demonstrated this by comparing their forecasts during volcanic eruptions to the observed temperature data. (These comparisons were made in IPCC TAR – a time when the IPCC was afflicted with a bout of honesty).
    The main point is that although the models predicted temperature drops of 0.4 or 0.5 C, the actual drops were only about 0.1c. The world isn’t that sensitive to volcanic climate forcings, so maybe Laki is exonerated after all.

  15. Wait, wait, wait, wait. You mean by engaging in proper scientific processes the cause of both harsh winters may actually now have an known cause other than blaming volcanoes or AGW? Whoa!!!! Better not let the “Team” know about this, it could cause a few heads to explode. Do not assume that I am dismissing volcanic influences on weather/climate, but rather am pleased to see real science being conducted in finding other possible causes that don’t include worthless models and a lot of verbal claptrap.

  16. I consider that the use of tree-ring reconstruction analysis is completely valid in this case, because it is not a time-line comparison, but a comparison of how trees responded to otherwise similar atmospheric conditions – i.e. one with the Laki eruption and the NAO/ENSO, while the other was NAO/ENSO only.

  17. “The eruption spewed out toxic sulfuric acid aerosols, which spread over northern latitudes and caused thousands of deaths.”
    Mostly Fluor that poisoned grazing cows and led to famines.

  18. If were you colonials I’s blame good old blighty! Everybody else does, it’s always our fault, even our pathetic excuse for a Prime Minister blames it all on Britain. That year was 33 years after we started the Industrial Revolution that everyone hates, well the water mellons do! It must have been caused by Co2 from Britiasn northern workshops & factories! Sarc off:-) Also more seriously, why can’t it be a combination of both volcanic & AMO/ENSO/AO? S£%t does happen sometimes, ask the Japanese!

  19. First you have to believe they can get a 2 degree temp reconstruction from trees…
    …rocks, ice, corals, diatoms, potatoes

  20. It’s rather obvious that the dominant signal is the cyclical change and the volcano was merely adding some amount to the misery index.
    Any time natural periodic oscillation(s) can be detected and a reasonable prediction can thereby be derived this suffices as the bulk of any explanation excepting of course the extraordinary.
    In that vein if we can reliably detect natural oscillation showing (e.g.) warming or cooling in Europe over 20 year period A then claims of volcanos, aliens, or GHGs emitted by nefarious and evil corporations are of equal value.
    The lottery is a tax on those who can’t do math. AGW politics is a tax on everyone based on the realisation that over 50% of us play the lottery.

  21. Paul Westhaver says:
    April 6, 2011 at 7:15 am
    Maybe, just keeping an open mind here, there is a relationship between the oscillation and the likelihood of eruption. Maybe they go hand in hand?…sometimes?
    Maybe effectually, but almost certainly not causally. An atmospheric oscillation, although impressive in scope, has no influence on plate tectonics whatsoever. Like AdderW says, the volcanoes of Iceland don’t give a rat’s patoot about our weather forecasts.

  22. It may be that the impact of volcano eruptions is exaggerated.
    For example, the fingerprint of the Krakatoa 1883 eruption is not readily apparent in the temperature records/reconstructions (see the GISS record for 1880 to 1885).

  23. Wikipedia: Laki
    http://en.wikipedia.org/wiki/Laki
    “…The Laki eruption and its aftermath has been estimated to have killed over six million people globally, making it the deadliest volcanic eruption in historical times. The drop in temperatures, due to the sulfuric dioxide gases spewed into the northern hemisphere, caused crop failures in Europe, droughts in India, and Japan’s worst famine….”

  24. If we are going to play the game of worry, we need to be just as worried about a happenstance June frost paired with an early winter as the inconveniences of gradual global warming. The Twentieth Century was benevolent in terms of the climate for our crops. If history has anything to teach, things could also turn worse due to cold.

  25. I am not an expert on volcanic climatology, but there is a precedent that Laki may be the guilty party. In 1829 there was another major volcanic eruption in Kamchatka which is also in the higher latitudes. CET winter for 1830 was exactly same as one for 1784, following the Laki’s eruption. However coldest winter on the record was in 1740 when Shikotsu erupted, the next Agung 1963, then Lacki, Kamchatka and 1879.
    http://www.vukcevic.talktalk.net/CET-D.htm

  26. “In June 1783 the Laki volcano in Iceland began to erupt, and continued erupting for months, causing a major environmental disaster.”
    How can it be an environmental disaster when it is part of the environment? It’s hard to take this seriously at all after the first sentence.

  27. This in only one alternative hypothesis to the effects of Loki, so it is quite an overstatement to say that Loki was “exonerated” for the 1783-84 harsh winter. I’m sure this is far from settled.

  28. This post illustrates two of your oft-repeated deficiencies in scientific comprehension. First, you believe in results you like as a matter of faith. This is just published. Results like this need other scientists to confirm their validity. Saying “Icelandic volcano exonerated” is seriously jumping the gun.
    Second, you consistently seem to think that attributing causes is an either-or game. If the Sun affects the climate, then greenhouse gases can’t. If internal variation could have caused a very cold winter, then a volcanic eruption couldn’t have. etc etc. In nature, few things have one single cause, and many factors generally contribute.
    Still, your third frequent failing – misunderstanding and/or misrepresenting articles – is at least apparently absent in this case.

  29. Icelandic volcano exonerated for harsh winter of 1783–1784
    Will an ‘official pardon’ be granted to the falsely maligned volcano? The poor dear……..

  30. Hmmm… so you have Agung in ’63… El Niño for winter ’63/64. El Chichon erupts in ’82… super El Niño for winter ’82/83. Pinatubo blows in ’91. Strong El Niño for ’91/92.
    That’s how it works… especially for tropical volcanoes… but I still think with the amount of SO2 emitted by Laki, that an El Niño could have formed. You get enough stratospheric SO2 to cool the troposphere, you slow down the trade winds and voila… on comes El Niño.
    But then when you have a strong sun, the reduction in cloud cover increases solar radiation in the tropical Pacific, increasing trade winds and creating La Niña conditions.. which suppress blocking by strengthening and flattening the Pacific jet while moving it further north. Colder air stays bottled up in the northern U.S. and Canada and in Siberia. Europe sees mild, wet winters.

  31. SteveO
    “This post illustrates two of your oft-repeated deficiencies in scientific comprehension. ”
    Is the summary inaccurate? Rather, this post is a straightforward report on a very much on-topic finding, accompanied by no discussion, cheering, or told-you-so.
    The headline is hardly beyond today’s journalist practices, regardless of bias.
    It’s news. You are prejudically reading between the lines.

  32. @vukcevic says:
    April 6, 2011 at 10:15 am
    Agung was after the 1962/3 winter.
    The 1783/4 winter is fact the best astronomical analogue for the 1962/3 winter. Check 22nd Oct 1783 and 13th Nov 1962 for a reference, and then see the same configuration at 7th Jan 1010AD, when the River Nile froze that winter: http://www.fourmilab.ch/cgi-bin/Solar/action?sys=-Sf

  33. John Johnston says:
    April 6, 2011 at 3:32 am
    “Exonerated?” Maybe, maybe not. We have here two phenomena – the Laki eruption and the NAO/ENSO circumstances. The correlations suggest both as candidate causes.
    So this could be a case of “And” rather than “Or”.
    ===============================
    Right!
    The “either / or fallacy”…well NASA Goddard is invovled so I am not surprised by any LACK of fallacy….but your observations are intuitively correct.
    Why can’t it be a combination of both, or more?
    Would love to hear Bastardi’s take on this one….
    Chris
    Norfolk, VA, USA

  34. R. Gates says:
    April 6, 2011 at 10:59 am
    This in only one alternative hypothesis to the effects of Loki, so it is quite an overstatement to say that Loki was “exonerated” for the 1783-84 harsh winter. I’m sure this is far from settled.
    =======================
    Call the press. I find myself agreeing 100% with R Gates. There is a first for everything. 🙂
    Chris
    Norfolk, VA, USA

  35. How foolish! This study conclusively shows that the proper combination of NAO and ENSO causes volcanos to errupt. No other explanation is reasonable! 🙂

  36. The paper by Spencer and Braswell demonstrated how to pick between the difference between an ENSO related cooling and the Pinatubo (volcanic dust-aerosol) cooling event. In Spencer, R. W., and W. D. Braswell (2010), On the diagnosis of radiative feedback in the presence of unknown radiative forcing, J. Geophys. Res., 115, D16109, doi:10.1029/2009JD013371, their figure 4 showed the response to the 2007-2008 ENSO event to be very different to the Pinatubo event.
    Similar data should be able to pick the difference in the 2009-2010 event, whether it was largely an Eyjafjallajökull erruption event, an ENSO event or a combination.
    If the data showed it to be an Eyjafjallajökull erruption event then D’Arrigo et al. are probably wrong.

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