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.
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!
The article can be found here at Colombia University: http://www.ldeo.columbia.edu/~jsmerdon/papers/2011_grl_darrigoetal.pdf
Agust
Iceland
“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”.
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?
“The authors analyzed… tree ring reconstructions”
A phrase that always sends chills up my spine.
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.
“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.
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.
How long will it be before the fair-ground psychics ditch the tea-leaves and start using tree-rings like everyone else?
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!!
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
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?
I don’t think the volcano cares …
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?
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?
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.
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.
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.
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.
“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.
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!
First you have to believe they can get a 2 degree temp reconstruction from trees…
…rocks, ice, corals, diatoms, potatoes
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.
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.
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).