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.
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….”
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.
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
“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.
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.
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.
Icelandic volcano exonerated for harsh winter of 1783–1784
Will an ‘official pardon’ be granted to the falsely maligned volcano? The poor dear……..
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.
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.
@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
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”.
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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
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.
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Call the press. I find myself agreeing 100% with R Gates. There is a first for everything. 🙂
Chris
Norfolk, VA, USA
comparison of solar cycle 4 and 23
http://www.robertb.darkhorizons.org/DeepSolarMin.htm
Slightly off topic but connected, Myrdalsjokull continues to rumble away
http://en.vedur.is/earthquakes-and-volcanism/earthquakes/myrdalsjokull/
Tremors have moved from around the more famous Eyjafjallajokull to either around the summit area of Myrdalsjokull over the months since Eyjafjallajokull stopped erupting.
Will the bigger volcano erupt in the coming months?
Andy
How foolish! This study conclusively shows that the proper combination of NAO and ENSO causes volcanos to errupt. No other explanation is reasonable! 🙂
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.